Download Direct View/Projection Television Troubleshooting

Training Manual
KV-36HV500
KV-57WV700
Direct View/Projection
Television Troubleshooting
DA-4 & DA-4X Chassis
Models:
DA-4
KV-32HS500
KV-32HV600
KV-34XBR800
KV-36HS500
KV-36XBR800
KV-40XBR800
DA-4X
KP-57WV600
KP-57WV700
KP-65WV600
KP-65WV700
Theory of Operation & Practical Troubleshooting Tips
Course: C31P15
Table of Contents
1. DA-4 & DA-4X Introduction and
PCB Interconnection ............................1
5. DA-4 & DA-4X Video Procesing ....45
Introduction ............................................................ 1
Overall Block Diagram ........................................ 45
DA-4 & DA-4X PCD Interconnection ................. 1
6. DA-4 & DA-4X Chassis
Deflection Circuit .................................51
2. New Features (DA-4 Chassis) .........6
Scrolling Index ....................................................... 6
Digital Visual Interface (DVI) ............................... 6
Memory Stick® Interface ...................................... 8
3. Power Supply
(DA-4 & DA-4X Chassis) .....................12
DA-4 Chassis Power Supply .............................. 12
DA-4X Chassis Power Supply ........................... 20
DA-4 & DA-4X Regulators .................................. 26
4. DA-4 & DA-4X
Protection Circuits ...............................27
DA-4 Protection Circuits ..................................... 27
DA-4X Protection Circuits ................................... 37
DA-4 & DA-4X Acceptable Inputs .................... 45
Horizontal Drive Circuit ....................................... 51
DA-4 Vertical Deflection Circuit ......................... 53
DA-4X Horizontal Deflection Circuit .................. 54
DA-4X Vertical Deflectin Circuit ......................... 55
7. DA-4 & DA-4X Chassis
Communication Bus Networks ..........56
DA-4 & DA-4X Data Communication
Diagram ................................................................ 56
8. DA-4 & DA-4X Audio Circuits ........58
DA-4 & DA-4X Audio Block Diagram .............. 58
1. Introduction and DA-4 & DA-4X PCB Interconnection
Chapter 1 - Introduction and
DA-4 & DA-4X PCB Interconnection
Introduction
Overview
The C31P15 course covers the DA-4 (Direct View) and the DA-4X (Projection) chassis. The content includes
new features such as Memory Stick and DVI. Also included is theory of operation and troubleshooting tips for all
major circuits (Power Supplies, Protection, Deflection, Communications and Audio) in the DA-4 and DA-X chassis.
This training manual is based on the KV-32HV600 model.
Objectives
•
New Features
•
Circuit Theory of Operation
•
Component and Board level troubleshooting
DA-4 & DA-4X PCB Interconnection
Overview
The DA-4 (Direct View) and DA-4X (Projection) chassis share many of the same PCBs. The only differences are
found in the RGB Drive, Power Supply and Flash Focus circuits. Table 1-1 indicates the circuits found on each
PCB and if the PCB is board or component level repairable for both the DA-4 and DA-4X chassis.
Table 1-1 DA-4 & DA-4X PCB Circuits and Repair Information
Board
A
Circuits (DA-4)
•
•
•
•
•
•
•
•
AD
•
A/C
Input
STBY 5V
PS
+9V
Reg.
+3.3V
Reg.
+5V
Reg.
Main &
Sub.
Tuners
Audio
Output
IC’s
DYConv.
N/A
Circuits (DA-4X) Field
Reparability
•
•
Comments
A/C Input
STBY 5V
PS
+9V Reg.
+3.3V
Reg.
+5V Reg.
Main &
Sub.
Tuners
Audio
Output
IC’s
Possible
Component
Level Repair
No DY-Conv.
Circuit for DA4X Chassis
Board Level
Repair
DA-4X chassis
ONLY
•
Flash
Focus
Picture
Centering
•
5V Reg.
•
•
•
•
•
•
1
1. Introduction and DA-4 & DA-4X PCB Interconnection
B
•
•
•
•
•
•
•
•
•
•
•
•
•
C
D
H-Protect
V-Protect
AD-DRC
MID-XA
HD-ADC
CRT Drive
A/D DNR
Differential
Input
(Memory
Stick®)
+1.8V Reg.
+2.5V
Regs.
+3V Reg.
+3.3V Reg.
+5V Reg.
CH (HS) or
CX (HV/XBR)
• RGB Drive
•
H&V
Drive
• H & V DY
• Main
Power
Supply
+/-15V
+7V
+5V
+11V
+12V
+200V
+33V
Heater
• HV Power
Supply
• Protection
Circuits
HV Protect
+135
OVP/OCP
HD Protect
IK Protect
•
•
•
•
•
•
•
•
•
•
•
•
•
H-Protect
V-Protect
AD-DRC
MID-XA
HD-ADC
CRT Drive
A/D DNR &
SRAM
Differential
Input
(Memory
Stick®)
+1.8V Reg.
+2.5V Regs.
+3V Reg.
+3.3V Reg.
+5V Reg.
CR, CG, CB
• RGB Drive
•
•
•
•
H & V Drive
H&VD
HV Drive
Convergence
Amps
• +12V Reg.
• +5V Reg.
• +210V
• +135V
• Heater
• Protection
Circuits
HV Protect
HD Drive
+135 OVP/OCP
2
Board Level
Repair
Additional
Circuits on DA4X chassis:
•
•
•
Extra
VM
circuits
D-Brd
RGB
connecti
ons
SRAM
(IC3001)
Possible
Component
Level Repair
Separate RGB
drive boards in
DA-4X chassis
Possible
Component
Level Repair
Main Power
Supply located
on D-Brd in DA4 chassis.
Main Power
Supply located
on G-Board in
DA-4X Chassis
1. Introduction and DA-4 & DA-4X PCB Interconnection
DH
•
•
G
•
N/S
Correction
E/W
Correction
N/A
•
N/A
Power Supply
•
•
•
•
•
•
•
•
•
•
•
•
•
Unreg. 7V
Unreg. 5V
+/- 15V
+/- 19V
+135V
+33V
+12V
+36.5V
RY6701
RY6702
Key Input
LED
Remote
Control
Possible
Component
Level Repair
KV-40XBR800
ONLY
Possible
Component
Level Repair
DA-4X chassis
ONLY
Possible
Component
Level Repair
All models and
both Da-4 and
DA-4X chassis
Different Part#
for DA-4 & DA4X
HA
•
•
•
Key Input
LED
Remote
Control
HC
•
•
•
Key Input
LED
Remote
Control
•
N/A
Possible
Component
Level Repair
XBR models
ONLY
HB
•
Front
Video
Input
•
Front
Video
Input
Possible
Component
Level Repair
All models and
both DA-4 and
DA-4X chassis
Different Part#
for DA-4 & DA4X
HM
•
Memory
Stick®
•
Board Level
Repair
•
Terminal
Board
Memory
Stick®
Terminal
Board
All models and
both DA-4 and
DA-4X
chassis’s
Same Part# for
both DA-4 &
DA-4X
•
Main
System
Control
A/V
Processin
g
3D Comb
Filter
5V Reg.
•
Main
System
Control
A/V
Processin
g
3D Comb
Filter
Board Level
Repair
All models and
both DA-4 and
DA-4X chassis
Different Part#
for DA-4 & DA4X
M
•
•
•
•
•
•
5V Reg.
3
1. Introduction and DA-4 & DA-4X PCB Interconnection
MS1
•
Memory
Stick®
Processor
•
Memory
Stick®
Processor
Board Level
Repair
All models and
both DA-4 and
DA-4X
chassis’s
Different Part#
for DA-4 &
DA-4X
SR
•
N/A
•
Flash
Focus
Sensor
Board Level
Repair
DA-4X chassis
ONLY
U
•
A/V
Switch
Terminal
board
•
A/V
Switch
Terminal
board
UD
•
DVI
Decoder
•
DVI
Decoder
Board Level
Repair
All models and
both DA-4 and
DA-4X chassis
Same Part#
for both DA-4
& DA-4X
VM
•
N/A
•
Velocity
Modulatio
n
Possible
Component
Level Repair
DA-4X chassis
ONLY
W
•
Velocity
Modulatio
n
Vertical
Pincushio
n
N/S
Correction
•
N/A
Possible
Component
Level Repair
DA-4 chassis
ONLY
•
•
4
All models and
both DA-4 and
DA-4X chassis
Same Part#
for both DA-4
& DA-4X
1. Introduction and DA-4 & DA-4X PCB Interconnection
Figure 1-1 illustrates the PCB interconnections for both the DA-4 and DA-4X chassis.
DVI MOLEX
CONNECTOR
HA/HC (XBR)
KEYS
SIRCS
LED
UD
DVI
SPEAKERS
AC
INPUT
DY
CONVERTER
DGC
MS 1
HB
G
POWER
SUPPLY
DA-4X
CHASSIS
W
CR
VIDEO
OUT
B
AD DRC
MID - XA
HD - ADC
CRT DRIVE
AD DNR
VELOCITY
MOD.
V - PIN
N/S DRIVE
DA-4X
CHASSIS
CG
VIDEO
OUT
CRT
CRT
MEMORY
STICK
FRONT
A/V INPUT
HM
CB
VIDEO
OUT
MEMORY
STICK
INTERFACE
DA-4X
CHASSIS
HORIZONTAL &
VERTICAL
DEFLECTION YOKE
MEMORY
STICK PROCESSOR
V-PIN COIL
N/S COIL
QP COIL
A/V
SWITCH
VELOCITY
MOD
LANDING
CORRECTION
A
AC/DC POWER
AUDIO POWER
TUNER
DY CONV.,(DA-4)
U
VM
KV40XBR 800 ONLY
DH
MAIN MICRO
M
3D COMB
VIDEO PROCESSOR
AUDIO PROCESSOR
CCD,V-CHIP,ID1
A/V INPUTS
(1-7)
AUDIO OUT
MONITOR
OUT
S-CONTROL
ANTENNA
SWITCH
D
H/V DRIVE
H/V DY
POWER SUPPLY
AC RECT.
DEFLECTION
DIGITAL AD
REG
PJED CPU
PJE DRIVE
DA-4X
CHASSIS
DA-4
CHASSIS
SR
FLASH FOCUS
SENSORS
CH/CX(XBR)
CRT
VIDEO OUT
FIGURE 1-1 - DA-4 & DA-4X PCB BLOCK INTERCONNECTION DIAGRAM
5
CRT
1C31P15 1478
11/7/02
2. New Features (DA-4 Chassis)
Chapter 2 - New Features (DA-4 & DA-4X Chassis)
Three new features will be discussed in this section:
• Scrolling Index
•
DVI Interface
•
Memory Stick® Interface
Scrolling Index
The Scrolling Index allows you to select your
main video from a scrolling index of video
pictures.
The Scrolling Index appears with the currently
selected program in the main (left) window
and four scrolling video pictures in windows
down the right side of the picture tube.
As each picture on the right scrolls to the live
preview window, it changes briefly from a
frozen video to live video. The right side
continues to scroll through the entire channel
list.
Factors Affecting the Scrolling Index:
Ø Scrolling Index does not function
if you use a cable box to view all
channels.
Ø Sources connected to the AUX,
Video 5, Video 6 and Video 7 inputs
Figure 2-1
Scrolling Index
are visible in the left window, but not in the scrolling right windows.
Ø Scrolling Index does not function if the parental controls are set.
Digital Visual Interface (DVI)
Introduction
As the digital display technology (e.g. Plasma and LCD) grows so does the need to replace the present analog
HD component connection between external digital device (e.g. Digital TV/Satellite Receiver) and the HDTVTM
set. The issue is the inherent picture quality problems caused by Digital-to Analog (D/A) and Analog-to-Digital
(A/D) conversion processes.
For example, if you have a digital Plasma display HDTVTM and a Digital TV/Satellite Receiver, the digital video
signal in the Digital TV/Satellite Receiver must be converted to a analog component video signal and then sent
to the HDTVTM where it must be converted back to a digital signal video to drive the Plasma display. Because of
the two video signals conversion steps and the possible analog signal loss across the connection between the
HDTVTM and the Digital TV/Satellite Receiver, the picture quality will suffer. Even with an analog CRT the Digital
TV/Satellite Receiver video signal must go through D/A conversion, which can adversely affect picture quality.
The resolution to this dilemma is the creation of a complete end-to-end standard digital video interface, such as
DVI. The DVI interface is a high-speed digital video interface allowing uncompressed high-definition content to
be passed to another DVI equipped device such as an HDTVTM set. DVI is the only digital interface capable of
6
2. New Features (DA-4 Chassis)
accommodating uncompressed digital data such as HD video. DVI also has the bandwidth to support higher
audio fidelity.
DVI has a bandwidth of up to 5 Gigabits/sec, which is more then enough to accommodate an uncompressed HD
video transmission that typically requires 2.2 Gigabits/sec bandwidth.
DVI Connector and Decoding Block
The DVI Molex connector and Decoding circuitry for both the DA-4 and DA-4X chassis are located on the UDBoard (NOTE: This board is NOT field repairable). Figure 2-2 shows a block diagram for the UD-Board. The
DVI signal (from a Digital TV/Satellite Receiver) is received at the 24-pin Molex connector CN7001. There are
three serial data differential channels RX0+/RX0-, RX1+/RX1-, RX2+/RX2- and one reference clock differential
channel RXC+/RXC-.
IC7001 NVM is also connected to the external device through the SDA and SCL (I2C) bus. IC7001 stores the
EDID data (Extended Display Identification Data) and HDCP (High Definition Digital Content Protection).
EDID is sent to inform the external digital device of the TV’s identity and capabilities.
HDCP is an Authentication protocol between the external digital device (transmitter) and the TV (receiver) that
affirms to the transmitter that the receiver is authorized to receive the protected information.
CN 7001/pin 14 (5V) is supplied from the external digital device to power IC7001 (NVM) so EDID can be sent
when the TV set is OFF. If the TV set is ON, IC7001 will receiver 5V from CN7002 through D7001.
CN7001/pin 16 is the Hot Plug Detect pin (HPD). The TV set supplies 5V to the external digital device to verify
proper connection between the two devices.
CONNECTOR
R x 2+
R x 21
R x 1+
R x 0+
R x CSDA
R x 1R x 0R x C+
SCL
2
9
10
17
18
23
24
6
7
5V
14
HPD
16
CN7001
24P MOLEX
CONNECTOR
R7021
10kHz
IC7001
NVM
5V
3.3V 2.5V
5V TO
D7001
3.3V
REG
3.3V
2.5V
REG
2.5V
CN2304/
PIN 1
5V
5V
94
X7001
95
14.31818MHz
IC7004
DVI-DECODER
CN7002
10
8
6
SDA,
SCL
5V
2
X7002
12MHz
3
IC7005
MCU
SDA, SCL
IC7006
NVM
Y
PB
PR
13
4
3
SET-UP
2
RESET
5V
5V
1
MUTE
VGA
5V
FIGURE 2-2 - UD - BOARD BLOCK (DVI DECODER)
C31P15-2-2 1501
10/31/02
The DVI Decoder, IC7004 receives the three channels of digital video data and outputs analog component video
(Y, PB, PR) to CN7002/pins 10, 8 and 6 respectively.
7
2. New Features (DA-4 Chassis)
Memory Stick® Interface
Introduction
Memory Stick® is a new compact, portable and versatile Integrated Circuit Recording Medium with a data
capacity that exceeds that of a floppy disk. The internal memory circuit structure is a type of Flash Memory
similar to that found in a personal computer. It is a solid-state design, which basically means there are no moving
parts. Inside the Memory Stick® is a grid of columns and rows with a two-transistor cell at each intersection point
on the gird, which is used to store a 1 or 0. The Memory Stick® is specially designed for the exchange and
sharing of digital data among Memory Stick® compatible products such as Digital Still Cameras and Digital Video
Cameras. Because it is removable, Memory Stick® can also be used for external data storage.
Memory Stick® technology allows you to view on the TV digital (JPEG) still images that are stored on Memory
Stick® medium. You can choose from an index of the images stored on the Memory Stick® or you can run a
slideshow of those images.
The DA-4 and DA-4X chassis Memory Stick® viewer can display ONLY Still Images that have been recorded on
Memory Stick® media by Sony brand digital still and video cameras.
Recorded images must meet the following specifications:
Ø Compression format: JPEG
Ø File format: DCF compliant
NOTE: Most Sony brand digital still and video cameras automatically record still images using DCF
(Design rule for Camera File system) compliant directory and file names as shown in Figure 2-3:
IMAGE
DIRECTORY
NAME
100MSDCF
DSC0001
IMAGE FILE
NAMES
DSC0002
DSC0003
NOTE:
DO NOT RENAME DIRECTORIES.
IF THE NAMES ARE CHANGED,
THE STILL IMAGES CANNOT BE
DISPLAYED ON YOUR TV.
FIGURE 2-3 - DCF DIRECTORY
C31P15-2-3 1504
9/26/02
The main advantage of the Memory Stick® is its size, which measures approximately 2’’x3/4"x1/8", making it
extremely portable (reference Figure 2-3). However, do not let the size fool you; the Memory Stick® comes in
five data capacity ratings: 8MB, 16MB, 32MB, 64MB, 128MB and 256MB.
Note: The DA-4 and DA-4X chassis Memory Stick® viewer is compatible with Memory Sticks® up to and
including 128MB. **The 256MB Memory Stick® is not compatible.**
8
2. New Features (DA-4 Chassis)
MEMORY STICK
1/8"
TOP VIEW
2"
7/8"
1/8"
VIEW OF
LOWER
SIDE
LOCK
7/8"
2"
FIGURE 2-4 - MEMORY STICK DIMENSIONS
C31P15-2-4 1505
9/16/02
The DA-4 and DA-4X Memory Stick® viewer cannot display any of the following:
Ø Images recorded on digital still cameras and digital video cameras that are not Sony brand.
Ø Images recorded using products that are not DCF complaint, including the following Sony products:
•
Digital still cameras
DSC-D700
DSC-D770
•
Digital video cameras
DCR-TRV900
DSR-PD100A
Ø Images stored on a Memory Stick® that has a capacity that exceeds 128MB.
Ø Images stored in TIFF or any other non-JPEG compression format.
Ø Images in directories that were modified or renamed on a computer.
Ø Images with less than 16 horizontal and/or vertical dots per line.
Ø Images with more than 4096 horizontal and/or vertical dots per line.
9
2. New Features (DA-4 Chassis)
Memory Stick Interface and Processing Block
MEMORY
STICK
CN7201
HM BOARD
3.3V
MS-DIR+ MS-SCLK+ MS-SDO+ MS-SDI+ MS-INS
MS-BS+
MS-SDI
MS-DIR- MS-SCLK- MS-SDOMS-BS-
3
5
6
7
8
9
10
11
12
13
14
15
CN7202
B3
A4
BY
A5
B5
A6
B6
A7
B7
A8
B8
B9
CN3603
DIFF. - AMPS
& BUFFER
TO CRT
DRIVE
MID
B BOARD
CN3601
CN104
MS1 BOARD
MS DECODER BOARD
FIGURE 2-5 - MEMORY STICK INTERFACE & PROCESSING BLOCK
C31P15-2-5 1502
11/7/02
The Memory Stick® (MS) is inserted into CN7201 on the HM-Board. Once the MS is completely seated
in the slot, the Memory Stick® applies a ground to CN7202/pin 15 (MS-INS), which goes Low (from
3.3V to 0V). This notifies the MS1-Board that a MS has been inserted. Initial data will be transferred at
this time between the HM-Board and MS1-Board and can be viewed at CN7202/pins 5 through 14
(reference Waveforms 2-1 and 2-2). The data signals are all in differential format with a positive and
negative signal. The differential format is incorporated to eliminate noise on the data lines. Data can be
viewed on these pins when the MS is initially inserted and when an image is selected for display on the
CRT.
10
2. New Features (DA-4 Chassis)
CH2
.5v
100us
CH2
.5v
100us
Waveform 2-2
MS - SDI (-)
Waveform 2-1
MS - SDI (+)
The MS-INS is applied to the B Board/pin B3 and forwarded on to the MS1- Board. The MS-Data
signals are amplified on the HM-Board and then applied to the B Board/pins A4/B4 through A8/B8
where they are converted from differential format to single data lines, and further amplified and applied
to the MS1-Board.
The MS1 Board performs the following functions:
• Memory Stick® System Control
•
•
JPEG Processing
Memory Stick Decoding
The Memory Stick® JPEG data is then converted into digital Y, CB, CR data on the MS1 Board. The
digital Y, CB, CR data is then sent back to the B Board and is D/A converted to analog component video
signals (Y, CB and CR), which drive the CRT.
Troubleshooting Tips
1) All three boards (HM, Band MS1) are Not Field Repairable.
2) Confirm CN7202/pin 15 (MS-INS) goes low when Memory Stick® is inserted.
3) Confirm CN7202/pin 3 (3.3V supply).
4) Confirm CN7202/pins 5 through 14 have data activity during the following two events:
a. When the Memory Stick® is initially inserted; and
b. When an image is selected for display on the CRT.
5) Confirm the voltages and signals in steps 2, 3 and 4 are applied to CN3603/pins B3, A4/B4
through A8/B8 and B9.
6) If all voltages and signals are applied to the B Board, further troubleshooting will be board swap
due to inaccessibility to connectors on the B Board and MS1 Board.
There is not much signal processing performed on the B Board, so the most likely defect at this point
would be the MS1 Board.
11
3. Power Supply (DA-4 & DA-4X Chassis)
Chapter 3 - Power Supply (DA-4 & DA-4X Chassis)
This chapter will cover the power supply section for both the DA-4 and DA-4X chassis. The degauss circuit for
the DA-4 chassis will also be discussed.
The power supplies for the DA-4 and DA-4X chassis are almost identical except in the following two main areas:
1) High Voltage (HV) development: The HV on the DA-4 chassis is Switch-mode power supply derived, whereas
the HV on the DA-4X chassis is scan derived.
2) Circuit Location: On the DA-4 chassis, the power supply circuitry is located on the A and D-boards, whereas
on the DA-4X chassis, the circuitry is on the A, D and G boards.
Except for the development of the HV, the circuit operation for the Standby 5V and Main Converter Power
Supplies is identical. Notes and references are placed on each diagram where the circuit operation is
identical between the two chassis. The circuit itself may be located on a different board and component
reference numbers may be different, but the components are the same. As you read this section, note the
similarities and differences between the DA-4 and DA-4X chassis.
DA-4 Chassis Power Supply
DA-4 Overall Power Supply Block
VD501
T510 T511
STANDBY 5V
POWER
SUPPLY
AC
FH501
HA/HE BD.
STANDBY
5V CIRCUIT
M BD.
13V FROM 5V STBY
DGC
D503/C506
D501
TH501
Q502
RY501
+
R506
Q501
C507
A BOARD
1
2
GND.FROM
Q6527
(AC
RELAY)
RY6501
CN514
CN6502
FROM D508,D509
36.5V
+/- 15V
UNREG 7V
IC6501
MAIN
POWER
SUPPLY
UNREG 5V
UNREG 11V
+135V
+200V
D BOARD
R6516
AC-RECT
FROM AC RECT.
BLOCK D6530
RY6502
(INRUSH
RELAY)
FROM
UNREG
11V
DGC-ON
FROM
IC2300
/PIN 68
( M-BD.)
IC8002
HV POWER
SUPPLY
H-OUT
Q5030
T8001
FBT
HOT
T5001
IC5006
FIGURE 3-1 - DA-4 POWER SUPPLY OVERALL BLOCK
12
HV
G2
FV
ABL
DF
H1( HEATER)
C31P15-3-1 1509
10/28/02
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4 Overall Power Supply Block Description
Once 120V AC power is applied to the TV set (set plugged into the AC outlet), the Standby 5V power supply
(located on the A-board) is active and outputs regulated 5V (reference Figure 3-1). The STBY 5V is sent to the
M-board to partially power-up system control IC2300 and is also sent to the HA/HC board to power the Remote
Control Sensor (SIRCS).
The Main Converter power supply (DA-4) located on the D-board is fed AC (from A-Board) through the ACRelay (RY6501) and through Inrush-Current resistor (R6516). This limits the initial high current produced when
the TV set is first turned ON. The Inrush-Current resistor (R6516) is removed from the AC input path using
RY6501. Once the Main Converter power is up and running, the unreg11V output is fed back to RY6501, the
relay switch is closed and R6516 is bypassed in normal operation. The Main Converter power supply outputs the
following voltages:
•
+/- 15V
•
•
Unreg7V
Unreg5V
•
Unreg11V
•
36.5V
•
+135
•
+200
The High Voltage (HV) on the DA-4 chassis is developed using a switch-mode power supply identical to the one
found in the Main Converter power supply except for the use of the Flyback (FB) T8001 as the output transformer
(reference Figure 3-1). The HV power supply is located on the D-board. The HV power supply is activated
simultaneously with the Main Converter power supply. AC power is fed to the HV power supply from the ACRECT block (D6530), which also feeds the Main Converter power supply. The HV Converter output then drives
the FB transformer, which outputs the following voltages:
•
High Voltage (HV)
•
Focus Voltage (FV)
•
G2
•
ABL
The Heater Voltage is scan derived using H-Out (Q5030), T5001 and IC5006 also located on the D-board.
The Degauss Circuit (reference Figure 3-1) will be activated after IC2300 (M-board) receives an ON command
from either the ON/OFF button or the remote control, and after one of the following events have occurred:
•
The AC power was disconnected (indicating that the TV was possibly relocated).
•
The TV has been turned OFF for more then 15 minutes.
The base of Q501 receives a high from IC2300/pin 68 (turning Q501 ON). The ground path for the degauss relay
RY501 and the base circuit of Q502 are completed through the collector/emitter circuit of Q501. Q502 supplies
the initial kick voltage and current to RY501. Once C504 in the base circuit charges completely, Q502 will turn off
and a hold voltage is supplied through D501 (13V) from the STBY Power Supply circuit.
RY501 switch closes and sends AC through the degauss coil, eliminating any magnetic fields present in the
metallic parts in the picture tube, which could cause color purity problems. The degauss relay remains closed for
approximately six seconds and then opens.
13
3. Power Supply (DA-4 & DA-4X Chassis)
Three relay clicks will be heard when the set is first turned on in the following order:
1) Degauss Relay (RY501)
2) AC Relay (RY6501)
3) Inrush Current Relay (RY6502)
DA-4 STBY 5V Power Supply and Power-On Switching Circuit
T502
R510
L510 L511
AC
INPUT
C507
D503
FH501
R509
CN6502 CN514
2
2
CN523
19
19
CN2002
+
C506
CN900
CN5011
R6528
69
IC2300
R6509
R6530
7
7
TO D-BOARD
AC TO D6530
CN6701
A BOARD
TO RY501
DEGAUSS
RELAY
SOLENOID
HA/HC
BD.
+
Q2312
ON 20V
M IC2300
ON 9V
STBY 23V D508
BD. SYSCON
STBY 11V I
IC501 O
IC2302 NVM
D509 +
STBY 5V
Q503
IC2305 3.3V
C514
5V
REG
+
G
R513 +
ON-8.5V
C515
R516
STBY-22V
C513
CN521
8
5
CN6506
TO D6530
D6534
MAIN
POWER
R6516
ON 0.6V
(AC)
SUPPLY
STBY-0V
AC RELAY
RY6501
RY6502
R6519
(INRUSH)
Q6527
RELAY
M BOARD
D501
D BOARD
D6533
NOTE
CIRCUIT OPERATION IS THE SAME FOR BOTH DA-4 & DA-4X CHASSIS
UNREG 11V
OUTPUT FROM
MAIN POWER
SUPPLY
FIGURE 3-2 - DA-4 STANDBY 5V POWER SUPPLY & POWER ON SWITCHING CIRCUIT
C31P15-3-2 1508
11/12/02
Standby 5V Power Supply
Reference Figure 3-2 during the following circuit description:
The Standby Power Supply (located on the A-board) is operational as long as the set is plugged into an AC outlet.
AC power is applied to T502 through fuse FH501 and chokes L510 and L511. T502 couples the AC across to
D503 rectifier block and filter capacitor C507 (AC is also coupled to Q503; this is part of the power-on switching
circuit which will be discussed next).
The Standby 5V power supply is a simple conventional full-wave (only two diodes in D503 are used) rectifier
circuit. The resulting DC voltage (11V) is applied to the input pin of IC501 (5V regulator), which then supplies
regulated 5V to the following components:
•
IC2300 System Control (M-board)
•
IC2302 NVM (M-board)
•
IC2305 3.3V Regulator (M-board)
•
•
Q2312 Remote Input Buffer
HA/HC boards (Key Input, LED and Remote Sensor)
14
3. Power Supply (DA-4 & DA-4X Chassis)
Power-ON Switching Circuit
Reference Figure 3-2 during the following circuit description:
In the Standby mode, System Control (IC2300) is partially powered (using STBY 5V) and waiting for an ON
command from either the Front Panel Controls (IC2300/pins 93 and 94) or the Remote Control (IC2300/pin 7).
Once the ON command is received, IC2300/pin 69 (AC_RLY) outputs a high, which is applied to the base of
Q6527 (turning Q6527 ON). This completes the ground path for the AC Relay (RY6501) and for the base circuit
of Q503.
Q503 turns on and supplies the initial kick voltage and current through D508 to RY6501, closing the relay switch
and supplying AC power to the Main Power Supply through Inrush resistor R6516 and D6530. Once C513 in the
base circuit charges completely Q503 turns off; D508 reverse biases and D509 forward biases, supplying a hold
voltage (9V) to keep the relay switch closed in the ON mode.
At this point the Main Power supply is turning ON (operation will be discussed next). The initial AC power to the
Main Power Supply is through Inrush resistor R6516, which limits the high surge current that occurs momentarily
at turn ON. Once the secondary voltage UNREG 11V is developed on T6502 in the Main Power Supply, it is fed
back to the Inrush Relay (RY6502). RY6502 turns on and bypasses R6516 in the ON mode. R6516 is only in
the circuit during initial power-up of the set.
Troubleshooting Tip:
Obviously, if a failure occurs in the 5V Standby Power Supply the unit will not even attempt to turn ON. If this
condition occurs, check the following components:
1) FH501
2) 13V at IC501 Input Pin (I). If missing, suspect T502, D503 and/or C507.
3) 5V at IC501 Output Pin (O). If missing, suspect a defective IC501.
4) NOTE: Q503 is used as a current source for the AC relay (RY6501). If the collector/emitter junction of
Q503 becomes an Open circuit, the set will still turn ON (using voltage through D509) and function
properly with sufficient AC power input. If the AC power input is weak (Low Voltage ~90VAC, the unit will
have difficulty turning ON without Q503 functioning properly.
15
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4 Main Switching Power Supply Circuit
CN6701
CN514
TO A BD.
AUDIO VCC
(36.5V)
A-BOARD
1
1
D6530
AC RECT.
5
TO IC8002/PIN 1
HV POWER SUPPLY
2
4
1
CN6503
R6646
FILTER
CIRCUIT
D6514
1
IC6501
MCZ
3001D
VG
12
(L)
4.8V
VB
10.6V
C6508
10
6
+
C6519
PS6505
2
Q6507
16
275Vp-p
78kHz
D6504
6
+
7
15
OCP
TIMER
F/B
VCI
2
8
9
R6556
R6501
0V
R6539
R6505
+
NOTE:
C6558
TO IC8002/
PIN 8
D6520
+
C6559
-15V
+33V
C6502
D6508
33V
L6505
R6508
R6510
8
11
9
10
C6549
4
R6525
D6524
13
D6519
D-BOARD
+15V
C6597
+
14
18V
UNREG
11V
D6523
R6557 C6352
VC2
1.9V
CIRCUIT OPERATION
IS THE SAME FOR
BOTH DA4 & DA4X
CHASSIS'
D6516 UNREG
+
5V
17
Q6506
D6502
+
279V
141V
VG 16
(H)
136V
VS 15
2.7V V-SENSE
14
PS6506
18
R6536
18
R6517
+
L6516
1
R6514
R6513
T6502
+
R6526
UNREG
7V
D6513
C6546
FROM
RY6501
D6518
1
R6524
3
+15V
R6544
2.4V
2
PH6502
+
C6556
11V
R6503
+135V
L6501
+200V
+ C6557
R6590
IC6503
4 DM-58 1
133V
3 CONT.
C6551
FIGURE 3-3- DA-4 MAIN POWER SUPPLY CIRCUIT
5
C31P15-3-3 1506
11/8/02
The Main Switching Power supply is basically IC6501 (Switch Regulator Controller). IC6501 contains all the
major circuitry necessary to function as a switching power supply, except for the Power Switching MOSFETS
(Q6507 and Q6506).
IC6501 contains:
•
Control circuit
•
Oscillator/Oscillator control
•
Output Driver transistors
•
10V regulator
•
Shut-Off Timer
•
Over Current Protection
16
3. Power Supply (DA-4 & DA-4X Chassis)
Main Switching Power Supply Operation
Reference Figure 3-3 for the following circuit description:
AC signal is applied to the rectifier block D6530. The AC component is filtered-out by the filter circuit (shown in
block form). A DC voltage of 293V is produced at the output of the filter circuit.
IC6501 Startup Sequence
1) Turn ON voltage: The 293Vdc from the filter circuit is voltage divided by R6646, R6514, R6513 and
R6517 down to 2.7Vdc. This voltage is applied to IC6501/pin 1 (Vsense) and IC6501 turns ON. IC6501/
pin1 (Vsense) is also used for OVP protection (IC6501/pin 1 > 8V will trigger OVP).
2) Internal circuit Start Voltage: The 293Vdc also passes through voltage dropping resistors R6526 and
R6536, and 279Vdc is applied to IC6501/pin 18. This voltage is used to initially power the internal circuits
and begin oscillations. Note that the 293Vdc from R6526 is connected directly to the Drain of Q6507 and
serves as the High-side FET power source.
Internal circuits initially powered by IC6501/pin 18
•
Internal drive transistors for High-side output FET Q6507.
•
Oscillator
•
Control circuit
•
10V regulator (IC6501/pin 10)
Note: The 10V output at IC6501/pin 10 passes through D6502 and supplies power to the internal
driver transistor for the Low-side output FET Q6506
3) Output Oscillations: At this point, initial square-wave oscillations of approximately 125KHz are output at
IC6501/ pins 16 and 12. Normal operation frequency is approximately 85KHz.
4) Regulator Feedback: The feedback line is connected to the +135V secondary output. Once IC6501 is
turned ON and oscillations begin, the secondary winding at T6502/pin 13 and associated circuitry produces
+135V. The +135V is applied to IC6503/pin 1 (DM-58 Control).
IC6503 controls the voltage at the PH6502/pin 2, which controls the current output of the optic-coupler
PH6502. The amount of current supplied to IC6501/pin 2 depends on how hard PH6502 is turned ON. In
normal operation, a voltage of 1.9Vdc (which is proportional to the amount of current) is present at
IC6501/pin 2. The feedback loop is now complete.
5) IC6501 normal operating power supply (VC1): Produced simultaneously with the oscillator feedback is
the operating power source VC1.
IC6501/pin 8 (VC1) is produced using a winding on T6502/pin 8. The AC is rectified and filtered, and a
DC voltage of 18V is applied to IC6501/pin 8. Once the 24V is stable, IC6501’s internal control circuit
disconnects (internally) the power source at IC6501/pin 18. All IC6501 internal circuits are now powered
from IC6501/pin 8.
Over Current Protection (OCP): ref. Figure 3-3
The current flowing through the switching FETS (Q6507 & Q6506) also passes through T6502/pins 6 and 7,
C6532 and resistor bank R6557 and R6556. The voltage drop across resistor bank R6557 and R6556 is
directly proportional to the current through the switching FETS. The voltage across R6557 and R6556 is
further voltage divided by R6501 and R6505 and applied to IC6501/pin 9. The OCP is activated when the
voltage at IC6501/pin 9 exceeds 0.2V. The self-diagnostic indicator will flash four times, pause and then
repeat.
17
3. Power Supply (DA-4 & DA-4X Chassis)
Over Voltage Protection (OVP) and Under Voltage Protection (UVP): The voltage at IC6501/pin 8 (VC1) is
monitored by circuitry inside IC6501 for Under-voltage and Over-voltage conditions. The two conditions are
as follows:
OVP – greater than 33V
UVP – less than 8V
If either of these two conditions occurs at IC6501/pin 8, the unit will go into protection mode. The selfdiagnostic indicator will flash four times, pause and then repeat.
Troubleshooting Tips (ref. Figure 3-3)
NOTE: Follow previously discussed “IC6501 Startup Sequence”. The five steps are in order of occurrence.
NOTE: Use HOT GRND when making measurements on primary side of T6502. This includes all
measurements on IC6501.
Symptom: Unit goes into protection mode, LED flashes four times.
Check: This indicates either a Vertical deflection or power supply problem.
1) Check power supply secondary outputs.
•
If voltages are present and at proper the level, then the problem is in the Vertical deflection drive
circuit.
•
If the secondary voltages are low or missing, then the problem is in the power supply.
2) The power supply can be safely tested by unloading the +135v line. Unsolder R5013. This will unload
the +135V line of the power supply, but still send necessary feedback to IC6501 for proper power supply
operation.
3) If the power supply outputs proper secondary voltages after unsoldering R5013, suspect a shorted +135V
line
4) If the unit still goes into protection mode after unsoldering R5013, check the following items:
•
D6538 (5V Zener) for shorted condition.
•
Check IC6505 (B+ OVP) for proper operation.
•
IC6501/pin 15 (this is midpoint for output MOSFETS Q6507 and Q6506). A 275Vpp, 85KHz
square-wave should be present. If the waveform pulses four times and stops, check the next
Item.
•
IC6501 Feedback circuit. The amount of current feedback can be determined by monitoring the
voltage drop across R6525. The minimum current feedback is 80uA, which is a minimum voltage
drop of 37.6mV. In normal operation, this voltage drop is approximately 223mV. If the voltage
drop is below 37.6mV, suspect components in the feedback path e.g. PH6502 and IC6503.
Reference Figure 3-3 for proper voltages at these components.
•
If no waveform is present when the unit is turned ON, then check IC6501/pins 1 and 18 for proper
voltages (reference “IC6501 Startup Sequence” above).
If these voltages check OK, check IC6501/pin 8 for proper voltage of 24V. This is the voltage
used to power IC6501 after initial startup.
If 18V is present at IC6501/pin8, check IC6501/pin 10 for 10.2V. This voltage is developed using
the 18Vs and a voltage regulator circuit inside IC6501. If 10.2V is missing, suspect a defective
IC6501. Also check voltage at IC6501/pin 14 (Use battery powered DVM for this measurement
and use IC6501/pin 15 (VS) as ground ref.). The voltage at IC6501/pin 14 should be 10V. If the
voltage measured at IC6501/pin 14 is incorrect, check D618.
•
If all the above measurements check OK, suspect a defective IC6501.
18
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4 High Voltage (HV) Power Supply Circuit
R8054 R8055
FROM D6530
AC-RECT.
N/C
R8053
R8051
V-SENSE VG 16
IC8002 (H)
D8012
2.4V
R8056
MCZ
D8013
3001D
121V
15
VS
14 VB
111V
Q8013
R8061
D8010
VG
12
10.6V
(L)
4.8V
10
VC2
+
D8011
C8025
D8014
6 TIMER
OCP
+
9
C8033
F/B
VCI
1
2
1.9V
D-BOARD
0V
8
17V
FROM MAIN POWER
SUPPLY T6502/PIN 8
17
R8085
L8002
8
6
14
DYNAMIC
FOCUS
7
C8037
FV
FOCUS
R8049
6
5
2
R8010
3
7.4V
7
RV8002
+15V
8.9V
ABL
1
2.4V
R8017
IC8005 1
CONTROL R8014 R8015
2
+
3
PH8003
R8096
9
R8070
10V
1
D8030
13
D8022 R8072
4
TO
ARCING
PROTECTION
D8015 CIRCUIT
HV
Q8014
TO IC8001/PIN 5
PROTECT.
R8065
R8059
T8001
116V
R8058
-
18
7.4V
8
7.4V
IC8004
BUFFER
FIGURE 3-4 - DA-4 HV POWER SUPPLY CIRCUIT
5
D8009
15V
C31P15-3-4 1507
11/8/02
The HV Switching Power Supply uses the same switching IC as in the Main Power Supply (MCZ3001D).
So, the theory of operation of IC8002 will be identical to that of IC6501 (reference IC6501 Startup
Sequence text for details) except for the following differences:
IC8002/pin 18 is not used because VC1 is supplied from the T6502/pin 8 in the Main Power Supply
circuit. Pin 18 is only needed when the switching IC (MCZ3001D) must supply its own VC1 through the
output transformer.
19
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4X Chassis Power Supply
VD501 T510
T511
STBY 5V
POWER SUPPLY
AC
INPUT
STBY 5V
A BOARD
FH501
CN514
1
2
CN6701
FROM Q6503
UNREG 7V
(AC
RELAY)
UNREG 11V
RY6701
G BOARD
UNREG 5V
FROM D508,D509
MAIN
POWER
SUPPLY
& RELAYS
R6705
(INRUSH
RELAY)
12V
+/- 19V
+/- 15V
+36.5V
RY6702
+135V
FROM
IC6501
12V
33V
R8225
210V
T8004
T8006
Q8042
Q8041
H-DRIVE
D BOARD
+/- H HEATER
PS8007
H-OUT
Q8043
HV
T8005
FBT
ABL
FV
FOCUS
PACK
G2
DF
FIGURE 3-5 - DA-4X POWER SUPPLY OVERALL BLOCK
C31P15-3-5
10/16/02
The A-board in the DA-4X chassis is identical to the A-board in the DA-4 chassis except for small mute and
protections circuits, which will be discussed later. The 120V AC input is applied to the A-board and is applied to
the STBY 5V power supply. Regulator STBY 5V is sent to the M-Board to partially power system control
IC2300, and also to the HA/HC board to power the Remote Control Sensor (SIRCS).
The Main Converter power supply for the DA-4X chassis is located on the G-board. The circuitry and the
operation of the Main Converter power supply in the DA-4X are identical to the DA-4 chassis, except for three
additional output voltages: +/- 19V, 12V and 33V, and the exclusion of the +200V line.
•
+/-19V
•
+/- 15V
•
Unreg-7V
20
3. Power Supply (DA-4 & DA-4X Chassis)
•
Unreg-5V
•
Unreg-11V
•
12V
•
33V
•
36.5V
•
+135
The +200V, HV, FV, G2, and Heater are all scan derived on the D-board in the DA-4X chassis. The horizontal
output Q8043 drives T8004 to produce the +200 and Heater voltages, and also drives T8005 (FBT) to produce
HV, FV, G2 and ABL voltages.
•
High Voltage (HV)
•
Focus Voltage (FV)
•
•
G2
+200V
•
+/-Heater
•
ABL
DA-4X STBY 5V Power Supply & Power-On Switching Circuit
TO G-BOARD
AC TO D6702
CN6701
T502
L510 L511
AC VD501
INPUT
D503
FH501
ACRELAY
7
8
CN514
CN6701
19
19
HA/HC
BD.
+ C507
Q2312
ON 20V
M IC2300
STBY 23V
D508
BD. SYSCON
I
IC501 O
IC2302 NVM
+
D509
+ STANDBY 5V
Q503
IC2305 3.3V
C506
C514
5V
REG
+
R513
G
+
R516
C515
C513
7 CN900
CN523
CN2002 CN6506 8
8
6
M BD.
IC2300
CPU
ON 0.6V
STBY 0V
R6523
5
4
D6504
R6525
69
TO RY501
DEGAUSS
RELAY
D501
SOLENOID
ON 9V
STBY 11V
A BD.
CN521
TO D6702
MAIN POWER
SUPPLY
CN6506
R6705
RY6701
(AC
RELAY)
Q6503
D6524
RY6702
(INRUSH RELAY)
G BD.
R6530
12V
FROM
IC6501
D6501
NOTE:
CIRCUIT OPERATION IS THE SAME FOR BOTH DA4 & DA4X CHASSIS'
FIGURE 3-6 - DA-4X STANDBY 5V POWER SUPPLY & POWER ON SWITCHING CIRCUIT
C31P15-3-6A 1514
21
11/7/02
3. Power Supply (DA-4 & DA-4X Chassis)
Standby 5V Power Supply
Reference Figure 3-6 during the following circuit description:
The Standby Power Supply (located on the A-board) is operational as long as the set is plugged into an AC outlet.
AC power is applied to T502 through fuse FH501, and chokes L510 and L511. T502 couples the AC across to
D503 rectifier block and filter capacitor C507 (AC is also coupled to Q503 this is part of the power-on switching
circuit which will be discussed next).
The Standby 5V power supply is a simple conventional full-wave (only two diodes in D503 are used) rectifier
circuit. The resulting DC voltage (13V) is applied to the input pin of IC501 (5V regulator), which then supplies
regulated 5V to the following components:
•
IC2300 System Control (M-board)
•
IC2302 NVM (M-board)
•
IC2305 3.3V Regulator (M-board)
•
•
Q2312 Remote Input Buffer
HA/HC boards (Key Input, LED, and Remote Sensor)
Power-ON Switching Circuit
Reference Figure 3-6 during the following circuit description:
In the Standby mode, System Control (IC2300) is partially powered (using STBY 5V and 3.3V), and waiting for an
ON command from either the Front Panel Controls (IC2300/pins 93 and 94) or the Remote Control (IC2300/pin
7) (circuit not shown).
Once the ON command is received, IC2300/pin 69 (AC_RLY) outputs a high, which is applied to the base of
Q6503, turning Q6503 ON. This completes the ground path for the AC Relay (RY6701) and for the base circuit
of Q503.
Q503 turns on and supplies the initial kick voltage and current through D508 to RY6701, closing the relay switch
and supplying AC power to the Main Power Supply through Inrush resistor R6705 and D6702. Once C513 in the
base circuit charges completely Q503 turns off; D508 reverse biases and D509 forward biases, supplying a hold
voltage (9V) to keep the relay switch closed in the ON mode.
At this point the Main Power supply is turning ON (operation will be discussed next). The initial AC power to the
Main Power Supply is through Inrush resistor R6705, which limits the high surge current that occurs momentarily
at turn ON. Once the secondary voltage UNREG 11V is developed on T6703 in the Main Power Supply, it is fed
back to the Inrush Relay (RY6702). RY6702 turns on and bypasses R6705 in the ON mode. R6705 is only in
the circuit during initial power-up of the set.
Troubleshooting Tip:
Obviously, if a failure occurs in the 5V Standby Power Supply the unit will not even attempt to turn ON. If this
condition occurs, check the following components:
1) FH501
2) 13V at IC501 Input Pin (I). If missing, suspect T502, D503, and/or C507
3) 5V at IC501 Output Pin (O). If missing, suspect a defective IC501.
4) NOTE: Q503 is used as a current source for the AC relay (RY6701). If the collector/emitter
junction of Q503 becomes an Open circuit, the set will still turn ON (using voltage through D509)
and function properly with sufficient AC power input. If the AC power input is weak (Low Voltage
~90VAC), the unit will have difficulty turning ON without Q503 functioning properly.
22
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4X Main Switching Power Supply Circuit
D6519
A-BOARD
CN6701
CN514 1 1
C6560
R6702
FROM
RY6701&
RY6702
R6508
L6701
D6702
T6703
7
R6710
36.5V
+
R6712
R6711
UNREG
5V
PS6508
PS6509
9
279V
D6511
18
D6502
17
18
R6714
2.7V 1 V-SENSE VG
D6712
16
275Vp-p
78kHz
10
+
6
D6515
PS6503
+19V
1
PS6504
R6728 C6711
-19V
2
10.6V
+
C6519
Q6701
IC6701 (H) 136V
MCZ
VS 15
3001D
Q6702
146V
VG
14 VB
12
(L)
4.8V
R6721
C6726
141V
16
15
UNREG
11V
D6503
VC2
R6729
OCP
TIMER
F/B
2
0V
18V
G-BOARD
+
R6730
PS6502
+
4
R6713
C6727
-15V
D6538
12
3
11
D6518
PS6507
D6514
R6506
4
1
3
2
IC6501
12V
+
10
R6732
D6537
13
D6715 D6716
C6723
+
C6724
PS6505
+15V
D6535
8
1.9V
D6534
14
R6731
9
VCI
UNREG
7V
C6553
C6525
+19V
R6733
PH6001
4
11V
IC6503 1
DM-58
CONTROL
5
+135V
R6518
R6505
133V
33V
D6517
36V
FIGURE 3-7 - DA-4X MAIN POWER SUPPLY CIRCUIT
CP31P15-3-7 1513
11/6/02
The Main Switching Power supply is basically IC6701 (Switch Regulator Controller). IC6701 contains all the
needed circuitry necessary to function as a switching power supply, except for the Power Switching MOSFETS
(Q6701 and Q6702).
IC6701 contains:
•
Control circuit
•
Oscillator/Oscillator control
•
Output Driver transistors
•
10V regulator
•
Shut-Off Timer
•
Over Current Protection
23
3. Power Supply (DA-4 & DA-4X Chassis)
Main Switching Power Supply Operation
Reference Figure 3-7 for the following circuit description:
AC signal is applied to the rectifier block D6702. The AC component is filtered-out by the filter circuit (shown in
block form). A DC voltage of 293V is produced at the output of the filter circuit.
IC6701 Startup Sequence
1) Turn ON voltage: The 279Vdc from the filter circuit is voltage divided by R6710, R6711, R6714 and R6721
down to 2.7Vdc. This voltage is applied to IC6701/pin 1 (Vsense) and IC6701 turns ON. IC6701/pin1
(Vsense) is also used for OVP protection (IC6701/pin 1 > 8V will trigger OVP).
2) Internal circuit Start Voltage: The 279Vdc also passes through voltage dropping resistors R6702 and
R6712, and 291Vdc is applied to IC6701/pin 18. This voltage is used to initially power the internal circuits
and begin oscillations. Note that the 279Vdc from R6702 is connected directly to the Drain of Q6701 and
serves as the High-side FET power source.
Internal circuits initially power by IC6501/pin 18
•
Internal drive transistors for High-side output FET Q6701
•
Oscillator
•
Control circuit
•
10V regulator (IC6701/pin 10)
Note: The 10V output at IC6701/pin 10 passes through D6712 and supplies power to the internal
driver transistor for the Low-side output FET Q6702
3) Output Oscillations: At this point, initial square-wave oscillations of approximately 125KHz are output at
IC6701/ pins 16 and 12. Normal operation frequency is approximately 85KHz.
4) Regulator Feedback: The feedback line is connected to the +135V secondary output. Once IC6701 is
turned ON and oscillations begin, the secondary winding at T6703/pin 11 and associated circuitry produces
+135. The +135V is applied to IC6503/pin 1 (DM-58 Control).
IC6503 controls the voltage at the PH6001/pin 2, which controls the current output of the optic-coupler
PH6001. The amount of current supplied to IC6701/pin 2 depends on how hard PH6001 is turned ON. In
normal operation, a voltage of 1.9Vdc (which is proportional to the amount of current) is present at
IC6701/pin 2. The feedback loop is now complete.
5) IC6701 normal operating power supply (VC1): Produced simultaneously with the oscillator feedback is
the operating power source VC1.
IC6701/pin 8 (VC1) is produced using a winding on T6703/pin 4. The AC is rectified, filtered and a DC
voltage of 18V is applied to IC6701/pin 8. Once the 24V is stable, IC6701’s internal control circuit
disconnects (internally) the power source at IC6701/pin 18. All IC6701 internal circuits are now powered
from IC6701/pin 8.
Over Current Protection (OCP): ref. Figure 3-7
The current flowing through the switching FETS (Q6701 and Q6702) also passes through T6703/pins 1 and
2, C6711 and resistor bank R6728 and R6729. The voltage drop across resistor bank R6728 and R6729 is
directly proportional to the current through the switching FETS. The voltage drop across R6557 and R6556
is further voltage divided by R6731 and R6730 and applied to IC6701/pin 9. The OCP is activated when the
voltage at IC6701/pin 9 exceeds 0.2V. The self-diagnostic indicator will flash four times, pause and then
repeat.
Over Voltage Protection (OVP) and Under Voltage Protection (UVP): The voltage at IC6701/pin 8 (VC1) is
monitored by circuitry inside IC6701 for Under-voltage and Over-voltage conditions. The two conditions are
as follows:
OVP – greater then 33V
24
3. Power Supply (DA-4 & DA-4X Chassis)
UVP – less then 8V
If either of these two conditions occurs at IC6501/pin 8, the unit will go into protection mode. The selfdiagnostic indicator will flash four time times, pause and then repeat.
Troubleshooting Tips (ref. Figure 3-3)
NOTE: Follow previously discussed “IC6701 Startup Sequence”. The five steps are in order of occurrence.
NOTE: Use HOT GRND when making measurements on primary side of T6703. This includes all
measurements on IC6701.
Symptom: Unit goes into protection mode, LED flashes four times.
Check: This indicates either a Vertical deflection or Power Supply problem.
1) Check power supply secondary outputs.
2) If voltages are present and at the proper level, then the problem is in the Vertical deflection drive circuit.
3) If the secondary voltages are low or missing, then the problem is in the power supply.
4) The power supply can be safely tested by unloading the +135v line. Unsolder l6514. This will unload the
+135V line of the power supply, but still send necessary feedback to IC6701 for proper power supply
operation.
5) If the power supply outputs proper secondary voltages after unsoldering l6514, suspect a shorted +135V
line. Check the Horizontal Output transistor (Q505 or 506) for shorted conditions.
6) If the unit still goes into protection mode after unsoldering lC6514, check the following items:
•
IC6701/pin 15 (this is midpoint for output MOSFETS Q600 Q6701 and Q6702). A 275Vpp, 78KHz
square-wave should be present. If the waveform pulses four times and stops, check the next
Item.
•
IC6701 Feedback circuit. The amount of current feedback can be determined by monitoring the
voltage drop across R6732. The minimum current feedback is 80uA, which is a minimum voltage
drop of 37.6mV. In normal operation, this voltage drop is approximately 223mV. If the voltage
drop is below 37.6mV, suspect components in the feedback path, e.g. PH602 and IC604. Reference
Figure 3-7 for proper voltages at these components.
•
If no waveform is present when unit is turned ON, then check IC6701/pins 1 and 18 for proper
voltages (reference “IC600 Startup Sequence” above).
If these voltages check OK, check IC600/pin 8 for proper voltage of 18V. This is the voltage used
to power IC6701 after initial startup.
If 18V is present at IC6701/pin8, check IC6701/pin 10 for 10.2V. This voltage is developed using
the 18Vs and a voltage regulator circuit inside IC6701. If 10.2V is missing, suspect a defective
IC6701. Also check voltage at IC600/pin 14 (Use battery powered DVM for this measurement,
and use IC6701/pin 15 (VS) as ground ref.). The voltage at IC6701/pin 14 should be 10V. If the
voltage measured at IC6701/pin 14 is incorrect, check D6712.
•
If all the above measurements check OK, suspect a defective IC600.
25
3. Power Supply (DA-4 & DA-4X Chassis)
DA-4 & DA-4X Regulators
DA-4 & DA-4X Regulator Interconnect Diagram
D BOARD
DA4X ONLY
IC8010 O
+5V
I
UNREG 7V
G
DA4 & DA4X
A BOARD
*IC8004 (DA4X)
+15V
I
IC6500
O
12V REG
12V
G
IC504
O
5V REG
I
5V
G
UNREG 7V
UNREG 5V
UNREG 11V
12
12
11
11
8
8
7
7
4
4
3
3
I
I
CN6507
3.3V
G
CN524
G-BOARD (DA4X)
IC502
O
3.3V REG
IC505
O
9V REG
9V
G
D-BOARD (DA4)
CN6504
FIGURE 3-8 - DA-4 & DA-4X REGULATOR INTERCONNECT DIAGRAM
C31P15-3-8
10/9/02
The interconnect diagram shown in Figure 3-8 illustrates how the unregulated voltages produced on the D-board
(DA-4) and G-board (DA-4X) are used to develop other regulated voltages.
The unreg. 7V is used to develop reg. 5V through IC504; unreg. 5V is used to develop 3.3V through IC502;
unreg. 11V is used to develop reg. 9V through IC505. Also, note that in the DA-4X chassis, the unreg. 7V is used
to develop a separate reg. 5V on the D-board. In both the DA-4 and DA-4X chassis the reg. +15V is used to
develop regulated 12V.
26
4. DA-4 & DA-4X Protection Circuits
Chapter 4 - DA-4 & DA-4X Protection Circuits
DA-4 Protection Circuits
M BOARD
Overall Block Diagram
SYSCON
IC2300
CHASSIS
TEMPERATURE
(7X)
PROTECTION
TH5002
(2X)
AC-RELAY
AC RELAY
RY6501
DATA
D BOARD
CRT DRIVE
IC2801
B+ OCP
Q5004
Q6527
LATCH
Q6532
Q6530
B BOARD
FBT
OCP
(7X)
VIDEO MUTE
Q8008
(4X)
VERTICAL
DEFLECTION
PROTECTION
IC5004
INRUSH
PROTECTION
RELAY
RY6502
V-PROT
B+ OVP
IC6505
(6X)
(3X)
HV POWER SUPPLY
IC8002
LOW B+ 5V
PROTECTION
IC504, Q527
EXCESSIVE HV
PROTECTION
IC8001
IK WHITE BAL.
PROTECTION
(5X) IC9001, IC9002,
IC9003
FBT OCP
(AC SHUT OFF)
Q8007
(7X)
(7X)
A BOARD
(6X)
LOW HV
PROTECTION
IC8006
HORIZONTAL
DEFLECTION
PROTECTION
IC8006
HOT
GROUND
SECTION
IK PROT
(7X)
(6X)
CH/CX BD.
FIGURE 4-1 - DA-4 PROTECTION CIRCUITS OVERALL BLOCK
C31P15-4-1
10/30/02
Figure 4-1 is a basic block diagram illustrating the interconnection of the protection circuit, System control and
the AC relay. Also shown on the diagram is the Standby/Timer LED flash sequence for when the particular
protection circuit is triggered (e.g. 4X will occur with a vertical deflection failure). Each protection circuit will be
discussed in greater detail in coming diagrams. The purpose for each protection circuit is indicated by the name
of the particular block.
27
4. DA-4 & DA-4X Protection Circuits
The important thing to note on this diagram is the protection circuits that have a direct connection to the CPU and
those that do not. The protection circuits that have a direct connection will produce a more reliable flash sequence
e.g. 2X, 3X, 4X, and 6X. The circuits that do not have a direct connection may produce a 7X or 6X flash
sequence.
TH5002 is used to monitor the temperature of Q5031 (S-Correction Output). If this transistor should become a
short circuit, the current will increase which causes an increase in temperature. TH5002 detects the rise in
temperature, the Video is muted and AC input is disconnected through IC2801 (CRT Drive) and data
communications with IC2300 (Syscon).
Q5004 monitors the current draw on the +135V line. If the current should increase, video is muted via IC2801
and IC2300. Also note that there is a direct connection from the B+ OCP circuit and IC2300 Syscon for quick
disconnection of AC input.
Q8008 monitors the current in the secondary of the FBT using the ABL voltage. If excessive current flows in the
FBT, Q8008 is used to mute the video. Q8008 works simultaneously with Q8007, which turns off the AC relay.
IC5004 is the vertical deflection output drive IC. A feedback pulse is produced at IC5004/pin 3. If a vertical
failure occurs, the feedback pulse is not produced and the video is muted (AC input and Audio remain ON).
Q2314 monitors the 5V dc level. If the dc level falls below 4.5V, Q2314 detects this error and the AC input is
disconnected.
IC9001, 9002, and 9003 on the CH/CX board are the cathode drive ICs. Each IC produces a separate IK pulse
directly proportional to the current in each cathode. The current in each cathode indicates the physical condition
of the cathode. Depending on the cathode condition the set will either increase RGB drive to the cathode or go
into IK Protection mode.
RY6502 is used to bypass the Inrush Current resistor from the AC input circuit after initial set turn-on. If the relay
failures to activate, AC input is disconnected.
IC8006 monitors the HV output. If the HV is low, IC8006 detects this condition and the AC input is disconnected.
IC6505 monitors the +135 voltage level. If the voltage increases, IC6505 will disconnect the AC input.
Q8007 monitors the current in the FBT secondary. If the current increases, Q8007 will disconnect the AC input.
Q8007 works simultaneously with Q8008, which mutes the video output.
IC8001 monitors the HV level. NOTE: this circuit is on the HOT (or primary) side of the transformer, so use
HOT Ground for measurements. If the HV increases, IC8001 will turn off the HV converter IC8002.
IC8006 monitors the horizontal deflection output drive. If the horizontal deflection stops, IC8006 will turn-off the
HV converter IC8002.
28
4. DA-4 & DA-4X Protection Circuits
DA-4 Direct AC-Relay Shut-Off Protection Circuits
FROM IC2300
AC_RLY
M-BOARD
R6528
R6509
R6532
R6530
TO AC RELAY
Q6527 RY6501
Q6530
+135V
D-BOARD
Q6532
TO
IC2300
CPU
(INRUSH)
0V
D6505
C6596
R8040
+
R6537
R6538
(B+ OVP)
D6537
0V
R6605
0V
D8005
0V
D5007
R8039
FBT
(OCP)
(LOW HV)
R8038
15V
+
Q6522
R6527
R6602
C6595
R6545
15V
UNREG.
11V
4
IC6505
3
1
R8032
IC8006
COMPARATOR
+ 3
+135V
FROM
D6524
R6521
2.2V
R8028
15V
RY6502
+
C8017
R8027
1
2
R6507
D6533
C8012
+
R8036
R6593
1
R8043
Q8007
134V
PH6501
R8037
R8030
15V
0V
D8023
5.1V
R8022
R8033
2
3
12V
D8028
5.1V
+
R6593
C8052
UNREG.
11V
D6532
R8017
2
FBT
PIN 1
(ABL)
R8032
2.5V
R8035
R8025
R8014 TO IC8002
PIN 2
2.5V FEEDBACK
R8015
RV8002
(INRUSH
RELAY)
FROM
AC RELAY
RY6501
R6516
FROM
FBT
6
PIN 13 7.4V
TO AC
RECT. D6530
5
D8009
15V
+
7
7.4V
IC8004
BUFFER
FIGURE 4-2 - DA-4 DIRECT AC-RELAY SHUT-OFF PROTECTION CIRCUITS
C31P15-4-2 1517
11/15/02
As shown in Figure 4-2, four protection circuits, when triggered, will turn off the AC relay directly. The circuits
are as follows:
1) Inrush protection relay
2) B+ OCP
3) Low HV protection
4) FBT OCP
29
4. DA-4 & DA-4X Protection Circuits
Inrush Current Relay Protection Circuit
(Reference Figure 4-2)
The current rating of the AC relay (RY65010) is 117mA at 153VAC. To keep the current below 117mA resistor
R6515 (Inrush Current Resistor) is in series with the AC input during the initial power-up of the TV. After the
initial power-up current surge, R6516 is bypassed when RY6502 (Inrush Relay) is energized and the switch is
closed.
The operation of RY6502 is monitored using R6516 and PH6501. If RY6502 does not function, a voltage drop
will develop across R6515, which in turn develops a voltage across R6507. The voltage across R6507 turns on
the LED and 11V is output on PH6501/pin 3. D6505 is now forward biased and a High is applied to the base of
Q6532, turning it ON, which then applies a Low to the base Q6530, turning it ON. Q6532 and Q6530 is a
latching circuit.
Once the latch is activated, the voltage at the base of Q6527 is reduced and it turns OFF, removing the ground
path for the AC Relay and it turns OFF. The TV shuts down and the Stby/Timer LED flashes a 7X sequence.
B+ OVP
(Reference figure 4-2)
The voltage level of the +135V line is monitored using IC6505. If the +135V increases at IC6505/pin 2, the
voltage at IC6505/pin 2 will decrease. Once IC6505/pin 2 decreases by 0.6V, Q6522 will turn ON. D6537 is now
forward biased and a High is applied to the base of Q6532, turning it ON, which then applies a Low to the base
Q6530, turning it ON (activating the latch).
Once the latch is activated, the voltage at the base of Q6527 is reduced and it turns OFF, removing the ground
path for the AC Relay and it turns OFF. The TV shuts down and the Stby/Timer LED flashes a 3X sequence.
Low HV Protection Circuit
(Reference Figure 4-2)
The HV level is monitored through the HV Regulator circuit. IC8004 and resistor network RV8002, R8017,
R8014 and R8015 are part of the HV regulator circuit. A sample of the HV is output at FBT/pin 13 and is applied
to IC8004/pin 5 (Buffer). Approximately 7.4V is produced at IC8004/pin 7, which is then applied to the resistor
network. Approximately 2.5V is developed at the junction of R8014, R8015 and R8017.
R8014 is the feedback path for IC8002 (HV Power Supply Converter IC) to keep the HV regulated.
R8025 is the path for the Low HV detection circuit. When the 2.5V at IC8006/pin2 decreases below the reference
voltage 2.2V at IC8006/pin3, a High will be output at IC8006/pin 1 (approximately 14V) through pull-up resistor
R8032. Zener diode D8028 (5.1V) will break down. D5007 is now forward biased and a High is applied to the
base of Q6532, turning it ON, which then applies a Low to the base Q6530, turning it ON (activating the latch).
Once the latch is activated, the voltage at the base of Q6527 is reduced and it turns OFF, removing the ground
path for the AC Relay and it turns OFF. The TV shuts down and the Stby/Timer LED flashes a 6X sequence.
FBT Over Current Protection (IK-Prot. 2)
(Reference Figure 4-2)
The secondary current in FBT is monitored by Q8007 at FBT/pin 1 (ABL). The +135V is used as the reference
voltage through the resistor voltage divider consisting of R8040, R8039, R8038, R8037 and R8043. The combined
voltage drop across R8036 and R8035 is used to turn off Q8007 and trigger the protection circuit. In normal
operation, 0.6V is applied to the base of Q8007, turning it ON and a Low is present at the collector. A High at the
collector is needed to activate the protection mode.
As the current in the FBT secondary increases, the ABL line will increase current through the voltage divider
network at the top of R8035 and less current will flow through R8035. The voltage drop across R8035 will
decrease, causing the combined voltage drop across R8036 and R8035 to decrease. At the same time, the 0.6V
at the base of Q8007 is decreasing, which turns OFF Q8007 and a High will be developed at the collector
through pull-up resistor R8022. Zener diode D8023 (5.1V) will break down. D8005 is now forward biased and a
30
4. DA-4 & DA-4X Protection Circuits
High is applied to the base of Q6532, turning it ON, which then applies a Low to the base Q6530, turning it ON
(activating the latch).
Once the latch is activated, the voltage at the base of Q6527 is reduced and it turns OFF, removing the ground
path for the AC Relay and it turns OFF. The TV shuts down and the Stby/Timer LED flashes a 7X sequence.
DA-4 Excessive HV and horizontal Deflection Protection Circuits
IC8002
HV
SWITCHING
CONVERTER
D-BOARD
(EXCESSIVE
HV PROTECTION)
Q8014
12
Q8013
V-SENSE
R8001
PH8001
C8007
R8069
4
1
3
2
15V
Q8003
+
D8024
6.2V
C8006
0V
7
A
+
C8002
(HORIZONTAL
DEFLECTION
PROTECTION)
D8001
D8072
R8078
C8041
IC8001
R8011
+
5
-
6
0V
B
-
2
+
3
IC8006
2.5V
5
1
NOTE:
HOT GROUND
SECTION
-
FBT
+
2.5V
6
2.2V
15V
3
2
7
R8072
R8052
IC8104
VREF.
15V
2.2V
R8046
1
C8021
TO LOW HV PROT
REF. FIGURE 4-2
FOR DETAIL
FBT
13
T8001
1
2.4V
Q8004
16
H
DRIVE
R8016
Q5030
H-OUT
R8135
5
4.5V 7.4V
R8136
TO
HORIZONTAL
DEFLECTION
YOKE
9V
Q5021
C5058 BUFFER
D8140
C5059
Q5025 (BUFFER)
C5060
19V
FROM T6502/PIN 8
R8137
D5018
15V
R5118
FIGURE 4-3 - DA-4 EXCESSIVE HV AND HORIZONTAL
C31P15-4-3 1518
DEFLECTION PROTECTION CIRCUITS
-15V
11/12/02
Excessive HV Circuit
(Reference Figure 4-3)
The HV is monitored at FBT/pin 5 using two comparator circuits (A & B) located in IC8001. Comparator A will be
triggered when there is a sustained excessive HV (or gradual HV increase), and comparator B will trigger on a
momentary (or fast increase) HV surge. Another way to look at these comparators circuits is that they are
backup circuits for each other (redundant circuits) to ensure shutdown under any excessive HV condition.
31
4. DA-4 & DA-4X Protection Circuits
Both comparators receive a sample of the HV from FBT/pin 5, which is input to IC8001/pin 5 and IC8001/pin3. A
reference voltage (Vref) of 2.2V is developed at IC8014/pin 3 and applied to IC8001/pins 2 and 6. Once the
voltage at either IC8001/pin 5 or 3 increases above the reference voltage due to an excessive HV conditions, a
High will be output at either IC8001/pin 7 or 1. The High output will turn ON either Q8004 or Q8003, which will
then apply a Low to IC8002/pin 1 (V-sense) turning the HV power supply converter IC OFF. Drive to the FBT will
stop and HV will not be developed.
The TV shuts down and the Stby/Timer LED flashes a 6X sequence.
Horizontal Deflection Protection
(Reference Figure 4-3)
A sample of the Horizontal drive pulse is taken off the top of C5060. The pulse at this point is amplitude limited
using D5018 to 15V. The sample pulse is first buffer by Q5021 and then applied to comparator IC8006/pin 5
through D8140. Approximately 7.4V is developed at IC8006/pin 5, making it more positive then the reference
voltage on IC8006/pin 6 (4.5V). This condition causes a High (15V) to be produced at the output of the comparator
IC8006/pin7. The 15V from IC8006/pin 7 is applied to the cathode side of the LED PH8001/pin 2, and 15V is also
applied to the anode side of the LED PH8001/pin 1. So, the LED is OFF and the collector/emitter junction at
PH8001/pins 4 and 3 is open. 2.4V is present at PH8001/pin 4.
If the horizontal drive to the deflection yoke (possible defective Q5030) were to cease, there would be no sample
pulse applied to IC8006/pin 5, and IC8006/pin 5 will go to 0V. This condition will cause IC8006/pin 7 to go Low.
This Low is applied to the cathode of the LED PH8001/pin 2, the LED turns ON and the collector/emitter junction
PH8001/pins 3 and 4 conduct applying ground to IC8002/pin 1 (V-Sense). This turns the HV power supply
converter IC8002 OFF and no drive to the FBT (HV output stops). With no drive to T8001, there will be no output
on T8001/pin 13. T8001/pin 13 is connected to IC8004/pin 7 and outputs a low to IC8006/pin 2. This will cause
a high to be output at IC8006/pin 1. This high will cause D8028 to break-over and a high will be applied to the
latch circuit of Q6532 & Q6530, and the AC relay will be shut-off.
The TV shuts down and the Stby/Timer LED flashes a 7X sequence.
32
4. DA-4 & DA-4X Protection Circuits
DA-4 Temperature (Q5031), B+OCP, Vertical Deflection Protection Circuits
M-BOARD
D-BOARD
AC RELAY
RY6501
69
B-BOARD
IC2300 SYSCON 31
IO-SDAT
52
IC2801
SDA
H-PROT.
V-PROT.
57
56
+135V
9V
D5006
R5104
R8040
9V
R8039
12V
0.7V
+C8015
Q5009
R8037
R8043
-
+
+
-
Q8008
4
5
9
8
+ R8031 R8036
C8018 R8035
7.5V
3V 0.23V
R8041
FROM
FBT/
PIN 1
(ABL)
15V
Q5005
BUFFER
(FBT OCP)
9V
+135V
+
C5054
R5108
9V
R5103
R5013
D5001
4.7V
+135V
TH5002
R5164
R8024
14
IC5007
1.6V
R5101
Q5010
R8038
0.7V
2
V-DY (-)
FEEDBACK
CN5002/PIN 5
D8007
Q5018
R5105
R2824
R5014
Q5004
D5005
R5019
R5023
3
(TEMPERATURE)
OF Q5031
FB PLS
R5016
R5004
R5009
R5017
TO M-BOARD
IC2300/PIN 44
R5011
IC5004
V-DRIVE
R5007
(VERTICAL
DEFLECTION
PROTECTION)
D-BOARD
+
C5006
R5012
(B+ OCP)
FIGURE 4-4 - DA-4 TEMPERATURE(Q5031), B+OCP, VERTICAL C31P15-4-4 1519 11/12/02
DEFLECTION, PROTECTION CIRCUITS
Q5031 Temperature Protection Circuit
(Reference Figure 4-4)
The temperature of the S-Correction transistor Q5031 is monitored using TH5002. If the temperature of
Q5031 should increase due to a defect, the resistance of TH5002 will decrease and the voltage at IC5007/pin 5
will decrease. Once the voltage level at IC5007/pin 5 decrease below the reference voltage level at IC5007/pin
4 (1.6V), the comparator output IC5007/pin 2 will go Low and turn Q5018 OFF.
A High through pull-up resistor R5104 is now applied to IC2801/pin 57 (H-Prot) through forward biased D5006.
IC2801 will mute the video and communicate via IC2801/pin 52 with IC2300/pin 31 to shut off the AC relay at
IC2300/pin 69.
33
4. DA-4 & DA-4X Protection Circuits
The TV video is muted, the AC relay shuts down and the Stby/Timer LED flashes a 7X sequence.
B+OCP Protection Circuit
(Reference figure 4-4)
The current in the +135V line is monitored using R5013 and Q5004. R5013 is the current sensing resistor. The
current in the +135V line flows directly through R5013. The voltage drop across R5013 in normal operation is
very low, approximately 0.2V. So, the +135V is passed with very little loss in normal operation. The voltage on
the left side is basically equal to the voltage on the right side of R5013, and because R5013 is connected across
the base/emitter junction of Q5004, there is no 0.6V difference across the junction and Q5004 is OFF.
When the current in the +135V line begins to increase due to a defect, the voltage drop across R5013 will also
increase. Because of the increased voltage drop across R5013, the voltage on the left side of R5013 will remain
constant but the voltage on the right side of R5013 will decrease. The decreased voltage on the right side is
applied to the base of Q5004 through D5005. Once the voltage drop across R5013 is large enough to cause a
0.6V difference across Q5004 base/emitter junction, Q5004 turns ON.
Current now flows through the voltage divider consisting of R5009, R5011 and R5012. The voltage drop across
R5012 is applied to IC5007/pin 8, causing IC5007/pin 8 to become more positive then the reference voltage at
IC5007/pin 9 (3V). The output IC5007/pin 14 will go Low and turn Q5018 OFF.
A High through pull-up resistor R5104 is now applied to IC2801/pin 57 (H-Prot) through forward biased D5006.
IC2801 will mute the video and communicate via IC2801/pin 52 with IC2300/pin 31 to shut off the AC relay at
IC2300/pin 69.
The TV video is muted, the AC relay shuts down and the Stby/Timer LED flashes a 2X sequence.
FBT Over Current Protection Circuit (IK Prot. 1)
(Reference Figure 4-4)
The secondary current in FBT is monitored by Q8008 at FBT/pin 1 (ABL). The +135V is used as the reference
voltage through the resistor voltage divider consisting of R8040, R8039, R8038, R8037 and R8043. The combined
voltage drop across R8036 and R8035 is used to turn off Q8008 and trigger the protection circuit. In normal
operation, 0.6V is applied to the base of Q8008, turning it ON and a Low is present at the collector. A High at the
collector is needed to activate the protection mode.
As the current in the FBT secondary increases, the ABL line will increase current through the voltage divider
network at the top of R8035 and less current will flow through R8035. The voltage drop across R8035 will
decrease, causing the combined voltage drop across R8036 and R8035 to decrease. At the same time, the 0.6V
at the base of Q8007 is decreasing, which turns OFF Q8007 and a High will be developed at the collector
through pull-up resistor R8022. D8007 is now forward biased through pull-up resistor R8024 and a High is
applied to IC2801/pin 57. IC2801 will mute the video and communicate via IC2801/pin 52 with IC2300/pin 31 to
shut off the AC relay at IC2300/pin 69.
The TV video is muted, the AC relay shuts down and the Stby/Timer LED flashes a 7X sequence.
Vertical Deflection Protection Circuit
(Reference Figure 4-4)
The operation of the vertical deflection circuit is monitored using the feedback pulse developed at IC5004/pin 3
(vertical drive IC). The pulse is amplitude limited using D5001 (4.7V Zener diode). The pulse passes through
buffer Q5005 and is applied to the base of Q5009, turning it ON, while applying a Low to the base of Q5010,
turning it OFF. With Q5010 OFF, the V-DY feedback will be applied to IC2801/pin 56 indicating proper vertical
deflection operation.
If the Vertical deflection should cease due to a defect, the feedback pulse at IC5004/pin 3 will not be developed
(no pulse through Q5005 buffer), Q5009 will turn OFF and Q5010 will turn ON. The V-DY will go to ground
IC2801/pin 56 detects the missing V-DY and places the TV in vertical shut down.
34
4. DA-4 & DA-4X Protection Circuits
In vertical shut down mode, only the video is muted, the AC power and Audio remain ON and the Stby/
Timer LED flashes a 4X sequence.
DA-4 Regulated 5V and White Balance Protection Circuit
AC RELAY
RY6501
69
M BOARD
I-LB-ERR
IC2300 SYSCON
IO-SDAT
43
81
D BOARD
2.8V
R2375
(REG. 5V
PROTECTION) Q2314
52
IC2801
CRT DRIVE
R2399
R2300
C2361
D2310
3.6V
24
B BOARD
IK_IN
12V
R2298
R9068
+
R9012
R9006
R9013
12V
Q9001
C9017
CH/CX BOARD
R9012
O
10.6V
UNREG
IC504
I 5V REG.
7V
Q9007
Q9015
Q9013
NOTE: 11V
R9025 WITH
WHITE
11V
RASTER
7
G
R9039
12V
A BOARD
7
12V
11V
R9020
11V
7
12V
IK
IK
IK
IC9001
RED
IC9002
GREEN
IC9003
BLUE
(WHITE BALANCE PROTECTION)
NOTE: IK_OUT ON HS MODELS
IS IC9001, 9002, 9003/PIN 5
FIGURE 4-5 - DA-4 REG. 5V AND WHITE BALANCE PROTECTION CIRCUITS
C31P15-4-5
10/28/02
Regulated 5V Protection Circuit
(Reference Figure 4-5)
The regulated 5V line is monitored using Q2314 and Zener diode D2310 (3.6V) on the M-board. The output of
the 5V regulator IC504 is applied to the emitter of Q2314. In normal operation Q2314 is turned ON and D2310
is conducting, holding the base at 3.6V. Approximately 2.8V is applied to System Control IC2300/pin 43, indicating
proper level of the regulated 5V line.
If the 5V line falls below approximately 4.5V at the emitter of Q2314, D2310 will stop conducting, Q2314 will turn
OFF and a Low will be applied to IC2300/pin 43. IC2300/pin 69 will then turn OFF the AC relay.
The AC relay shuts down and the Stby/Timer LED flashes a 6X sequence.
35
4. DA-4 & DA-4X Protection Circuits
White Balance Protection Circuit (IK Protection)
(Reference Figure 4-5)
The condition of each CRT cathode (RGB) must be monitored in order to maintain optimal white balance. Each
cathode is monitored by the individual driver IC9001, 9002 and 9003 on the CH/CX board. Each driver IC9001/
pin 7, IC9002/pin 7 and IC9003/pin 7 develops an IK feedback pulse, which is directly proportional to the current
drawn by each cathode in the CRT. The IK feedback pulse passes through buffer transistors Q9007, Q9015 and
Q9013, and then the sequence of the three IK feedback pulses is applied to the base of buffer Q9001.
The three IK feedback pulses are sequentially fed into IC2801/pin 24 and monitored for amplitude variations. If
the IK feedback pulse is Low in amplitude or is missing, this indicates a weak or defective cathode. IC2801/pin
24 will detect this condition and the unit will go into IK protection mode.
The TV video is muted, the AC relay will remain ON and the Stby/Timer LED flashes a 5X sequence.
36
4. DA-4 & DA-4X Protection Circuits
DA-4X Protection Circuits
Overall Block Diagram
M BOARD
LOW B+
(5V)
Q2314
AC-RLY
SYSCON
IC2300
AC RELAY
RY6701
DATA
Q6503
B BOARD
LATCH
Q6502, Q6504
G BOARD
IC2801
Y/C CRT DRIVE
D6523
D6526
IN RUSH
RELAY
PROTECTION
RY6702
(7X)
+15V
OVP
B+ OVP
IC6502
(2X)
(3X)
VERTICAL
DEFLECTION
PROTECTION
IC8003
N-DY(-)
HIGH
VOLTAGE
PROTECTION
IC8006
WHITE BALANCE
PROTECTION
CR, CT, CG
BOARDS
(7X)
(4X)
(7X)
(5X)
FROM
IC8008/PIN 10
FBT/PIN 11
ABL
FBT/PIN 6
FBT OCP &
LOW HV
PROTECTION
IC8007
(7X)
FBT OCP &
EXCESSIVE HV
PROTECTION
IC8006
D6527
B+ OCP
IC6502
HORIZONTAL
DEFLECTION
PROTECTION
IC8005
Q8044
FBT/PIN 11
ABL
D6525
AC-PROT.
Q528
A BOARD
D BOARD
SWITCH
Q8022
H-DRV
H-DRV
BUFFER
Q8041
H-DRV
SIGNAL
SWITCH
Q8021
(7X)
FIGURE 4-6 - DA-4X PROTECTION CIRCUITS OVERALL BLOCK
C31P15-4-6
10/28/02
Figure 4-6 is a basic block diagram illustrating the interconnection of the protection circuit, System control and
the AC relay. Also shown on the diagram is the Standby/Timer LED flash sequence for when the particular
protection circuit is triggered (e.g. 4X will occur with a vertical deflection failure). Each protection circuit will be
discussed in greater detail in coming diagrams. The purpose for each protection circuit is indicated by the name
of the particular block.
37
4. DA-4 & DA-4X Protection Circuits
(Reference Figure 4-6)
Q2314 monitors the 5V dc level. If the dc level falls below 4.5V, Q2314 detects this error and the AC input is
disconnected.
RY6702 is used to remove the Inrush Current resistor from the AC input circuit after initial set turn-on. If the relay
failures to activate, AC input is disconnected.
IC9101, 9201 and 9301 on the CR/CB/CG boards are the cathode drive ICs. Each IC produces a separate IK
pulse directly proportional to the current in each cathode. The current in each cathode indicates the physical
condition of the cathode. Depending on the cathode condition, the set will either increase RGB drive to the
cathode or go into IK Protection mode.
+15V OVP monitors the 15V line for excessive voltage condition.
IC6502 is used to monitor both +135V OVP and OCP conditions.
Q528 on the A-board. If AC is not present at the input to the Standby 5V circuit, Q528 will activate the Latch and
shut down the TV.
IC8005 and Q8044 monitor the horizontal deflection operation.
IC8003 and V-DY(-) IC8003 is the vertical drive IC that drives the deflection yoke (DY). The low side of the
deflection yoke is monitored for proper vertical operation.
IC8006 and IC8007 monitor three separate circuits: Low HV, Excessive HV and FBT OCP.
38
4. DA-4 & DA-4X Protection Circuits
DA-4 Direct AC-Relay Shut-Off Protection Circuits
R6525
FROM IC2300
AC RELAY
TO AC RELAY
RY6701
D6524
Q6503
R6523
R6504
R6526
Q6502
Q6504
C6575
(INRUSH)
(+15 OVP)
D6523
C6581
+
(B+ OCP)
D6507
+
R6528
(B+ OVP)
R6527
(AC PROT.)
D6525
D6526
D6527
R6538
+15V
12V
4
TO
SYSCON
IC2300
D6505
R6539
0V
1
3
7
IC6502
PH6002
+
1
3
2
IC6502
-
R6709
11
D6518 +135V
T6703
R6535
- +
2
6
0.7V
R6715
D6702
D6501
+135V
0V
REF.
5V
R6519
+
FROM T508/
PIN 8
CN6505
CN901
D528
5.1V
R6536
D529
Q528
5
2.4V R6516
REF.
5V
D6522
4.7V
2
2
R634
C572
11V
R561
+
R605
R6517
A-BOARD
12
12V
C6553
R6520
RY6702
R6506
G-BOARD
(INRUSH
RELAY)
FROM
AC RELAY
RY6701
R6705
TO AC RECT.
D6702
FIGURE 4-7 - DA-4X DIRECT AC RELAY SHUT-OFF PROTECTION CIRCUIT
C31P15-4-7 1520
11/15/02
Inrush Current Relay Protection Circuit
(Reference Figure 4-7)
The current rating of the AC relay (RY6701) is 117mA at 153VAC. To keep the current below 117mA, resistor
R6705 (Inrush Current Resistor) is in series with the AC input during the initial power-up of the TV. After the
initial power-up current surge, R705 is bypassed when RY6702 (Inrush Relay) is energized and the switch is
closed.
The operation of RY6702 is monitored using R6705 and PH6002. If RY6702 does not function, a voltage drop
will develop across R6705, which in turn develops a voltage across R6715. The voltage across R6715 turns on
the LED and 11V is output on PH6002/pin 3. D6523 is now forward biased and a High is applied to the base of
Q6504 turning it ON, which then applies a Low to the base Q6502 turning it ON. Q6504 and Q6502 is a latching
circuit.
39
4. DA-4 & DA-4X Protection Circuits
Once the latch is activated, the voltage at the base of Q6503 is reduced and it turns OFF, removing the ground
path for the AC Relay and it turns OFF. The TV shuts down and the Stby/Timer LED flashes a 7X sequence
+15 OVP
(Reference Figure 4-7)
The circuit monitoring the condition of the +15V line is a simple 20V zener diode. If the +15V line increases
above 20.6V, the Latch will be activated and the AC relay will be shut OFF.
B+OCP
(Reference Figure 4-7)
The current is monitored in the +135V line using resistor R6506 located in the ground-side of the +135V circuit.
If the current increases in the +135V line, the current through R6506 will also increase, but because of the
direction of the current through R6506, a negative voltage is developed an IC6502/pin 2. IC6502/pin 3 (Grnd)
will be now more positive then the negative IC6502/pin 2. a High is produced at IC6502/pin 1 and D6526 is
forward biased. The latch is activated and the AC relay is turned OFF. Note that the High from IC6502/pin1 is
also sent to System Control IC2300 to activate self-diagnostics.
B+OVP
(Reference Figure 4-7)
The B+ OVP circuit monitors the voltage level of the +135V through the voltage divider network consisting of
R6535, R6536, R6516 and R6517. If the +135V should rise, so will the voltage drop across R6517and the
voltage at IC6502/pin 5. Once the voltage at IC6502/pin 5 goes more positive then IC6502/pin 6, a High will be
produced at IC6502/pin 7 and D6525 will be forward biased. The Latch will activate and the AC relay will be shut
OFF. Note that the High from IC6502/pin7 is also sent to System Control IC2300 to activate self-diagnostics.
AC PROT
(Reference Figure 4-7)
The AC input to the Standby 5V circuit is monitored through D528, D529 and Q528. In normal operation D528 is
in break-over mode and Q528 in turned ON. If the AC input is missing, Q528 will turn OFF and a High will
forward bias D6527. the Latch will be activated and the AC relay will be shut OFF.
40
4. DA-4 & DA-4X Protection Circuits
DA-4X Horizontal, Vertical, IK, and HV Protection Circuits
IC2300
IO- 31
SYSCON SDAT
52
M BOARD
R8260 0V
V PROT
57
56
10
11
24
B BOARD
C2828
R2862
7
7
Q9102
R8036
D8051
0V
R8262
IC8005
HVDRIVE -
IK
Q9104
V-DY
Q8044
R8263
IC2801
Y/C CRT DRIVE
20
20
D8052
0.6V
TO
T8003/PIN 1
(HOT)
H PROT.
CN2804 21
CN510 21
CN508 8
CN803 8
A BOARD
IC8005/
PIN 16
V REG.
SDA
5
V-OUT
7
IC8003
VERTICAL
DRIVE
IC8006
3.6V
-
IK
IC9101
VIDEOOUT
CR BOARD
+
(V PROTECTION)
6
Q9202
5
+
12
7
7
IK
IC9201
VIDEOOUT
REF.
3.6V
Q8027
HORIZONTAL
B+ SWITCH
3
D8043
HV OVP
IC8006/
PIN 1
D8025
CG BOARD
BEAM
CURRENT
PROTECT
Q2028
IK 7
IC9301
VIDEOOUT
(HV -PROT.)
IC8005
HV DRIVE
(H PROTECTION)
Q9302
CB BOARD
D BOARD
(IK PROTECTION)
FIGURE 4-8 - HORIZONTAL, VERTICAL, IK, AND HV PROTECTION CIRCUIT
C31P15-4-8 1522
11/4/02
Horizontal Deflection Protection Circuit
(Reference Figure 4-8)
The horizontal pulse output at IC8005/pin 3 drives the +135V regulator transistor Q8027, which drives T8003/pin
1 (HOT). A sample of the horizontal pulse is taken from the terminal of Q8027, which is applied to buffer IC8005/
pin 12 and then to the base of Q8044. As long as the horizontal pulse is present at the base of Q8044, a low is
present at the collector.
If the horizontal deflection should stop the signal at the base of Q8044 will stop and a High will be produced at the
collector of Q8044, which will forward bias D8052. A High will now be applied to IC2801/pin 57 to blank the video,
and IC2801/pin 52 will communicate with IC2300/pin 31 and shut off the AC relay.
The standby/timer LED will flash a 7X sequence.
41
4. DA-4 & DA-4X Protection Circuits
HV Protection
(Reference Figure 4-8)
Also attached to the H-Prot. input IC2801/pin 57 is the HV-PROT. This circuit is actually monitoring two functions:
HV OVP and Beam Current through D8043 and D8025 respectively. If an excessive HV or Beam current condition
should occur, IC8006/pin 5 will go High, which will cause IC8006/pin 7 to output a High. The High will forward
bias D8051 and a High will now be applied to IC2801/pin 57 to blank the video. IC2801/pin 52 will then communicate
with IC2300/pin 31 and shut off the AC relay. The standby/timer LED will flash a 7X sequence.
Vertical Deflection Protection Circuit
(Reference Figure 4-8)
IC2801/pin 56 monitors the low side of the vertical deflection coil [V-DY (-)]. IC8003/pin 5 drives the high side of
the V-DY, while the other side goes to ground through R8036. A small vertical feedback signal is developed
across R8036, which is applied to IC2801/pin 56.
If the vertical deflection circuit should fail (no drive to V-DY), IC2801/pin 56 will detect the missing vertical
feedback signal and blank the video output to the CRT. The TV will be placed in Vertical shutdown and the
standby/timer LED will flash a 4X sequence. The AC Power and Audio will remain ON.
IK (White Balance) Protection Circuit
(Reference Figure 4-8)
Each CRT driver IC9101, 9201 and 9301/pin 7 (located on the CR, CG, and CB boards) produces an IK feedback
pulse directly proportional to the current in each cathode (which indicates the condition of the cathode). All three
IK feedback pulses are combined at Q9104 on the CR board and sent back sequentially to IC2801/pin 24.
Each pulse is monitored for level by IC2801/pin 24. If a pulse is low, IC2801/pin 52 will detect a weakened
cathode and IC2801 will increase the drive signal to that weakened cathode until optimal white balance is achieved.
If white balance cannot be achieve within two seconds then IC2801/pin 52 will communicate with IC2300/pin 31
and the TV will go into IK protection mode. The video to the CRT will be blanked and the standby/timer LED
will flash a 5X sequence. The AC power and Audio will remain ON.
42
4. DA-4 & DA-4X Protection Circuits
DA-4X HV OVP, and FBT OCP Protection Circuits
Q8042
C8160
Q8041
H-DRIVE
FROM
IC2801
T8006
HDT
7
+135V
D BOARD
Q8022
Q8021
R8198
R8132
R8131
0V
0V
1
0V
7
7
IC8007
+
-
R8195
0V
1
IC8006
-
+
+
-
R8194
-
+
R8193
3
2
6
5
3
2
6
5
+15V
R8192
REF.
D8008
(HV
OVP)
Q8029
IC8008
H-DRIVE
(FBT
OCP)
D8043 D8025
R8173
Q8028
R8153
10
R8157
+15V
D8023
R8151
R8150
R8169
REF.
R8191
R8219
6
D8038
3
5
C8129
T8005
FBT
(HV OVP)
PWM OUT
TO Q8035
FIGURE 4-9 - DA-4X HV OVP AND FBT
OCP PROTECTION CIRCUITS
11
ABL
R8190
C31P15-4-9
10/28/02
HV OVP and FBT OCP (or Beam Current) Protection Circuit
HV level and current are monitored by IC8006 and IC8007. They will stop high voltage generation to provide
protection for the HV components, CRTs and X radiation level. This is accomplished by disabling the H drive
pulse from the video processor IC2801 (not shown).
IC8007/pin 3 monitors a sample of the HV coming from the HV Block. If the HV should increase, IC8007/pin 3
will become more positive then the reference at IC8007/pin 2 and IC8007/pin1 will output a High. D8008 will now
forward bias and apply a High to IC8007/pin 5, and a High will be output at IC8007/pin 7. Q8022 will turn ON and
a ground will be placed on the emitter of buffer Q8041, stopping the H drive signal to T8006 and thus stopping
HV output.
IC8007/pin 5 can also be triggered through D8023. D8023 will be forward biased when an excessive beam
current condition exists in the CRT. The current in the FBT is monitored using the ABL voltage at FBT/pin 11. A
reference voltage is developed using the +135V and the voltage divider consisting of R8198, R8195, R8194,
R8193, R8192, R8191 and R8190. The combined voltage drop across R88191 and R8190 is used to turn off
Q8029 and trigger the protection circuit. In normal operation, 0.6V is applied to the base of Q8029 turning it ON
and a Low is present at the collector. A High at the collector is needed to activate the protection mode.
43
4. DA-4 & DA-4X Protection Circuits
As the current in the FBT secondary increases, the ABL line will pull increasingly more current through the
voltage divider network at the top of R8190 and less current will flow through R8190. The voltage drop across
R8190 will decrease, causing the combined voltage drop across R8191 and R8190 to decrease. At the same
time, the 0.6V at the base of Q8029 is decreasing, which turns OFF Q8029. A High will now be developed at the
collector through pull-up resistor R8173. D8023 is now forward biased and a High is applied to IC8007/pin 5. A
High will now be output at IC8007/pin 7 and Q8022 will turn ON and stop H drive at the emitter of Q8041,
stopping the HV.
IC8006/pin 5 has the identical function as that of IC8007/pin 5 just described. These are backup FBT OCP
protection circuits protecting against excessive beam current in the CRT. IC8006 uses Q8021 switch to stop H
drive at the emitter of Q8041.
IC8006/pin 3 protects against excessive HV the same as IC8007/pin 3. The difference between the two circuits
is where the HV is monitored. IC8007/pin 3 monitors HV at the HV Block whereas IC8006/pin 3 monitors the HV
using a coil in the primary side of the FBT located at FBT/pins 5 and 6. The output at FBT/pin 6 is directly
proportional to the HV. If HV increases, so will FBT/pin 6. The output is rectified, filtered and applied to IC8006/
pin 3. The function after a High is applied to IC8006/pin 3 is identical to IC8007/pin 3 described above except
Q8021 is used to stop the H drive at the emitter of Q8041.
The Standby/Timer LED flashes a 7X sequence when a failure occurs.
Regulated 5V Protection Circuit
SYSCON
IC2300
(I-LB-ERR)
43
R2375
Q2314
M BOARD
R2299
R2298
R2300
C2361
D2310
3.6V
O
G
A BOARD
IC504
5V REG.
I
UNREG. 7V
FIGURE 4-10 - REGULATED 5V PROTECTION CIRCUIT
C31P15-4-10
11/12/02
(Reference Figure 4-10)
The regulated 5V line is monitored using Q2314 and Zener diode D2310 (3.6V) on the M-board. The output of
the 5V regulator IC504 is applied to the emitter of Q2314. In normal operation, Q2314 is turned ON and D2310
is conducting holding the base at 3.6V. Approximately 2.8V is applied to System Control IC2300/pin 43 indicating
proper level of the regulated 5V line.
If the 5V line falls below approximately 4.5V at the emitter of Q2314, D2310 will stop conducting, Q2314 will turn
OFF and a Low will be applied to IC2300/pin 43. IC2300/pin 69 will then turn OFF the AC relay.
The AC relay shuts down and the Stby/Timer LED flashes a 6X sequence.
44
5. DA-4 & DA-4X Video Processing
Chapter 5 - DA-4 & DA-4X Video Processing
DA-4 and DA-4X Acceptable Formats
The acceptable inputs for these chassis are listed in Table 5-1:
Table 5-1 - DA-4 and DA-4X Inputs
Inputs
Format
Analog TV stations
Air (Ch. 2-69) or Cable (1-125) NTSC
Video 1-4
S or Composite Video (480i)
Video 5-6
Component Video (Y,PB,PR) 480i, 480p,
720p, or 1080i
Video 7 (DVI)
Digital 1080i
TO CH/CX BOARD
Overall Block Diagram
G
R
IC2801
CRT DRIVE
B BOARD
DRC
B
3.3V
MEMORY
STICK INPUT
MID
5V
9V
Y PB
CN3203
MAIN
TUNER
39
39
SUB
TUNER
49
49
CN513
46
46
9
9
CN2302
43
43
12
12
PB
Y
SUB YUV
IC2005
SUB-Y.C.T.
STBY
5V
H
V
37
37
VS
40 20 22 27 38 39
40 20 22 27 38 39
21
21
HS
25
25
Y
34
34
MEMORY
STICK 5V
PR
PB
31
31
28
28
48 50
48 50
A BOARD
CN525
49
49
PR
15
15
21
21
18 22 23 24 25
18 22 23 24 25
40
40
37
37
PR
VS
IC2008
YCT-SEL
HS
5V
9V
VS
34
34
16 17
16 17
PR
PB
HS
M BOARD
IC2200
MAIN
3D COMB
31
31
Y
MAIN YUV
IC2001
SUB-COMP
28
28
CN523
CN2002
5V-D
IC2006
COMPONENT IF
Y
IC2004
MAIN YC
PB
PR
CN2304
CN7002
DVI
DECODER
UD BOARD
A2 A9
A2 A9
63
B7 B20
B7 B20
60
A19
A19
56
58
SUB
SUB
MAIN
SUB
V/Y
C
TUNER TUNER
MONITOR
CV Y C CV Y C
V OUT
41
Q1506
MONITOR
J1503
8 10 12
15 17 19
VIDEO 1 VIDEO 3
J1501
B23
B23
A22
A22
B17
B17
4
44
MAIN
V/Y
MAIN
C
CV Y C
1
3
3
IC1502
AV SWITCH
CV
5
30
CN1501
CN1100
VIDEO 2
J1100
VIDEO 4
J1504
A16 B14 CN2006
A16 B14
CN1502
5
6
IC1505
VIDEO
SWITC
Y PB PR
H
Y OUT PB
PR
OUT OUT
Y PB PR
16 11 8
VIDEO 5
J1509
1 14 9
VIDEO 6
J1508
U BOARD
HB BOARD
FIGURE 5-1 - DA-4 & DA-4X VIDEO PROCESSING BLOCK
45
C31P15-5-1
10/15/02
5. DA-4 & DA-4X Video Processing
Video Processing Circuit Description
(Reference Figure 5-1)
The Main and Sub Tuners are located on the A board. The
video path is through the M board for each tuner starting at the
A board CN525/pins 39 and 49, which connects to the B board
CN2302/pin 39 and 49; CN2006/pins A9 & B7 (B board) then
connects to CN1502/pins A9 and B7 (U board). The video is
then input to IC1502/ pin 63 (Main) and IC1502/pin 60 (Sub)
the AV Switcher.
CH2
.5v
5 ms
Waveform 5-1
Sub and Main Tuner Video Output
The Sub video input is selected by IC1502 and the Main video is selected by either IC1502 or IC1505. Once the
inputs are selected, the Sub video is output at IC1502/pins 56 (V/Y) and 58 (C), and Main video is output at
IC1502/pins 44 (V/Y) and 47 (C) or IC1505/pins 3,5 and 6 (Component).
Video inputs 1, 3 and 4 are all located on the U board and are connected directly to IC1502 (as shown in Figure
5-1). Video input 2 is located on the HB board on the front of the TV and is also connected directly to IC1502.
Video inputs 1, 2, 3 and 4 can accommodate either Composite video or S-Video. The Sub and Main composite
outputs (Waveform 5-2) can be viewed on the U-board CN1502/pins B20 (Sub) and B23 (Main).
CH2
.5v
5 ms
Waveform 5-2
Sub and Main Video Output
The Sub and Main color signal outputs can be viewed on the U-board CN1502/pins A19 (Sub) and A22 (Main)
reference Waveform 5-3.
CH2
.5v
5 ms
Waveform 5-3
Sub and Main Color Signal Output
46
5. DA-4 & DA-4X Video Processing
Video inputs 5 and 6 are also located on the U board, but are connected to IC1505 Video Switch. Video inputs
5 and 6 are component inputs. The component signal outputs from IC1505 can be viewed at Cn1502/ pins B17
(Y), A16 (PB) and B14 (PR) reference Waveforms 5-4 and 5-5.
WAVEFORM 5-4
WAVEFORM Y SIGNAL 1.3Vp-p (H)
WAVEFORM 5-5
WAVEFORM PR SIGNAL 1.3Vp-p (H)
WAVEFORM 5-6
WAVEFORM P B SIGNAL 1.3Vp-p (H)
Note: These same component signals will also be present at CN2002/pins 9 (Y), 12 (PB), 15 (PR) for Sub and
Main video inputs, and CN2002/pins 28 (Y), 31 (PB), 34 (PR) for the component input for signal tracing.
The Horizontal (HS) and Vertical (HS). Sync. Input signals for both DRC and MID can be viewed at CN2002/pin
21 (DRC VS), CN2002/pin 18 (DRC HS), CN2002/pin 40 (MID VS) and CN2002/pin 37 (MID HS). (Reference
Waveforms 5-7 and 5-8 for VS and HS waveforms)
CH2
CH2
2V
50uS
2V
10mS
CH2
CH2
Waveform 5-7
Horizontal Sync
Waveform 5-8
Vertical Sync
47
5. DA-4 & DA-4X Video Processing
All the video signals pass through the A-board unprocessed and are then applied to the B-board through CN2002
(A-board) and CN3203 (B-board). All video processing is performed on the B-board (DRC and MID processing).
The DRC circuit will double the horizontal frequency for input signals with 15.75KHz (NTSC) horizontal inputs.
The MID circuit will up-convert the horizontal frequency of the input signal to 33.75KHz, which is the scan rate of
the DA-4 and DA-4X chassis. Table 5-2 shows the signal standard and its associate horizontal frequency.
Table 5-2 - Input Signal Standard and Horizontal Frequency
Input Signal
Horizontal Frequency
Standard NTSC 480i
15.534KHz
High Resolution 480p
High Resolution 720p
31.5KHz
45KHz
High Resolution 1080i
33.75KHzz
The following is a description of the signal flow for each standard listed in Table 5-2:
•
15.734KHz input: DRC circuit up-converts to 31.5KHz and MID circuit up-converters to 33.75KHz
•
31.5KHz input: MID circuit up-converts to 33.75KHz
•
33.75KHz input: XBR, HV pass through MID; HS bypass MID circuit
•
45KHz input: MID circuit down-converts to 33.75KHz
The output of the MID circuit is then applied to the CRT drive IC2801, which will then drive the CH/CX boards in
the DA-4 (shown in Figures 5-2 and 5-3, and CR, CG, CB boards in the DA-4X chassis (boards not shown, but
the circuit operation is same as Figure 5-2).
CX BOARD
CN2805 CN9001
R 1 1
Q9009
G 3 3
Q9010
R
2
V-IN
12
R
IC9001
B 5 5
12V 7 7
IK 8 8
Q9007
Q9001
G
B BOARD
Q9015
6
12V
7
IK
10
200V
V-IN
IC9002
6
12V
2
7
IK
10
200V
2
V-IN
12
G
CRT
D BOARD
B
Q9011
12
B
6
CN5003 CN9002
12V
IC9003
7 IK
Q9013
10
200V 1 1
200V
HEATER 4 4
NOTE:
CIRCUIT OPERATION IS IDENTICAL FOR DA-4X.
THE IC's ARE LOCATED ON SEPARATE BOARDS
(CR, CG, CB)
FIGURE 5-2 - DA-4 CX BOARD (HV & XBR)
48
C31P15-5-2 1524
11/12/02
5. DA-4 & DA-4X Video Processing
CH BOARD
Q9009
IC9001
R
V-IN
3
R 8
R 1
1
12V
IK
200V
G 3
3
2
5
6
B 5
5
12V 7
7
8
8
IK
G
Q9010
IC9002
3
V-IN
G 8
12V
IK
200V
2
5
6
CRT
Q9001
B BOARD
B
Q9011
D BOARD
200V 1
1
HEATER 4
4
IC9003
3
V-IN
B 8
12V
IK
200V
2
5
6
FIGURE 5-3 - DA-4 CH BOARD (HS)
C31P15-5-3
10/7/02
Troubleshooting (Board Level)
(Reference Figure 5-1)
The DA-4 and DA-4X chassis’s video processing circuits can be evaluated to board level simple by using the
various inputs. The following is a list of inputs versus the circuits active for that particular input.
Video Inputs 1-4: (480i Input)
IC1502 AV switch (U-board)
IC2001 and IC2200 Comb. (M-board)
IC2005 and IC2004 YCT (M-board)
IC2008 (M-board)
DRC circuit (B-board)
MID circuit (B-board)
IC2801 CRT Drive (B-board)
49
5. DA-4 & DA-4X Video Processing
Video Inputs 5 and 6: (1080i Input)
IC1505 Video Switch (U-borad)
IC2006 Component I/F (M-board)
Note: 480i will add the DRC circuit
before the MID circuit.
MID circuit (B-board)
IC2801 CRT Drive (B-board)
DVI Input
IC1505 Video Switch (M-board)
MID circuit
IC2801 CRT Drive (B-board)
Memory Stick Input:
MID circuit (B-board)
IC2801 CRT Drive (B-board)
Note that by applying signals to the various inputs, complete circuits and boards can be bypassed to determine
on which board the defective circuit is located. This is the most efficient way to troubleshoot the video processing
circuits because the M and B boards are not field repairable.
EXAMPLES:
(Reference Figure 5-1)
1) The Memory Stick Input will bypass the U and M boards.
2) The DVI Input will bypass the U board.
3) The Video 1-4 and Video 5-6 inputs can be used to isolate a defect to either IC1502 or IC1505.
50
6. DA-4 & DA-4X Deflection Circuits
Chapter 6 - DA-4 & DA-4X Chassis Deflection Circuits
DA-4 Horizontal Deflection Circuit
B BOARD
IC2801
Y/C
JUNGLE
4
HDR.
R5151
18 18
C5071
2 2
Q5035
CN2804 CN510
2.9Vp-p
HDT T5002
12Vp-p
Q5027
Q5030
H-OUT
R5130
1
+
-
2
HOT
T5001
1kVp-p
+135V
-5V (TO IC5005
CENTERING)
7
95V
5
C5041
8
6
L5003
REFERENCE
+
2
C5040
9
+5V (TO IC5005)
10
+15V
4
H-DY
D BOARD
TO IC4004
VERTICAL OUT
-15V
D5003
11
FROM CN5001/PIN 10
EW_PARA
Q5031
S-CORR C5064
FROM
CN5001/
PIN 10
(MP_PARA)
12
R5148
IC5001
Q5003
C5066
IC5002
7
+135V
1
2
4
+
6
HEATER (TO IC5005)
+
FROM
CN5001/
PIN 6
(HC_PARA)
4
Q5028
1
IC5005
H-CENT.
7
R5129
Q5036
A BOARD
FROM
T5001/
PIN 8
(REF)
Q5026
R5126
R5150
CN508 CN5009
C5070
152Vp-p
9V
+
-
5
7
-
6
+
5
6
C5030
33.75kHz
1Vp-p
10Vp-p FROM Q5006
FIGURE 6-1 - DA-4 HORIZONTAL DEFLECTION CIRCUIT
H-OUT
FEEDBACK
FROM T5001
11Vp-p
C3P15-6-1 1527
11/11/02
Horizontal Drive Circuit
(Reference Figure 6-1)
This circuit is split between an oscillator on the B-board and an output stage on the D-board. The 33.75KHz
horizontal oscillator is in the Y/C Jungle IC2801. IC2801/pin 4 outputs a 3Vpp rectangular waveform (H-DRV).
On the D-board, the H-DRV waveform is amplified through Q5035 and Q5036, and then applied to buffer Q5027.
The MOSFET driver Q5028 and the output transistor Q5030 amplify the signal to provide sufficient current to
drive the HOT T5001 and the H-DY deflection yoke.
At the output stage, the HOT T5001 has a secondary winding that provides filament voltage, and also +/-15V for
the vertical driver IC5004 and the horizontal centering circuit IC5005.
The waveforms shown on Figure 6-1 are the typical horizontal circuit signal shapes. The difference between this
set and a conventional set is the horizontal frequency, which is 33.75KHz as opposed to 15.75KHz scan rate in
the conventional set. The 33.75Khz scan rate is considered a high definition horizontal scan rate.
51
6. DA-4 & DA-4X Deflection Circuits
PWM Circuit
(Reference Figure 6-1)
The PWM circuit (Q5003) has two functions. First, it provides a regulated 102Vdc output for the horizontal
output transistor Q5030. Second, it compensates for horizontal pincushion affect and keeps the picture vertical
edges straight.
Regulator
The PWM circuit regulates +135Vdc from the power supply down to +102Vdc. Horizontal pulses from IC8004/
pin 1 (not shown in Figure 6-1) in the HV power supply section drive Q5003. The pulses are amplified and output
to the HOT T5001/pin 4. To control the output voltage, the output is sampled and used to change the pulse width
of the H drive pulses. These changes regulate the output voltage to +102Vdc at T5001/pin 4.
Pincushion Correction
If the PWM output voltage at T5001/pin 4 were changed, the horizontal picture size would vary accordingly. A
vertical pincushion signal is produced at IC2801/pin 11 (not shown) and is applied to the PWM circuit to increase
the picture width and compensate for the pincushion distortion.
The EW_PARA parabola signal form CN5001/pin 1 (D-board) is first applied to IC5001/pin 6 and output on
IC5001/pin 7, and then applied to IC5002/pin 5. The parabola signal at IC5002/pin 5 is compared to the sawtooth
waveform at IC5002/pin 6. This comparison causes the PWM signal at the output IC5002/pin 7 to vary in pulse
width. The change in pulse width causes more or less voltage to be applied to the horizontal output Q5030
collector during the vertical scan down the CRT. This varying voltage causes a varying current to be applied to
the H-DY. Current is gradually increased as the beam scans down until the current is maximum at the center of
the CRT where the pincushion distortion is the most extreme. The result is a good, straight line scan down both
sides of the CRT.
Heater Voltage
The filament voltage is applied when the horizontal oscillator signal produces horizontal sweep. The horizontal
output transformer T5001/pin 1 outputs 7.7Vdc when power is ON. This voltage is regulated to 6.1Vdc by
IC5006 to become the main filament voltage.
H-Centering and S-Correction
Also shown in Figure 6-1 is the H-Centering circuit. This circuit applies a small dc-offset to the H-DY to keep the
picture centered on the CRT. This function is performed dynamically through the service mode by varying the
parabola waveform at CN5001/pin 6 (HC_PARA). The HC_PARA after is applied to IC5005/pin 2 and a dc-offset
is produce at IC5005/pin 4.
The S-Correction circuit is used to correct for the slight “S” shaped distortion that appears in each horizontal
line. Once again this function is performed dynamically through the service mode by varying the parabola
waveform at CN5001/pin 10 (MP_PARA).
52
6. DA-4 & DA-4X Deflection Circuits
DA-4 Vertical Deflection Circuit
+15V
-15V
2
4
VCC
VD-
FB-PCS
V-OUT
BOOST
VD+
1
3
5
6
7
B BOARD
1.5Vp-p
IC2801
Y/C
JUNGLE
VD(-) 18
VD(+) 19
+
C5019
CN509 CN5001
2828
2727
D5002
V-PROT.
+15V
4 4
3 3
CN2804 CN510
A BOARD
Vee
IC5004
V-DRIVE
L5001
R5029
D BOARD
V-DY
1.7Vp-p
61Vp-p
R5046
R5051
C5024
1.9Vp-p
FIGURE 6-2 - DA-4 VERTICAL DEFLECTION CIRCUIT
C31P15-6-2 1528
11/8/02
Vertical Drive
The vertical oscillator inside IC2801 starts and outputs ramp signals at IC2801/pin 18 (VD(-)) and IC2801/pin 19
(VD(+)) when power is applied. Data need not be present for vertical drive to output from IC2801.
The vertical stage is has not changed functionally from previous models. The vertical drive signals from IC2801/
pins 18 and 19 are applied to IC5004/pins 1 and 7. The ramp signals are amplified in IC5004 and the output drive
for the V-DY is output at IC5004/pin 5.
53
6. DA-4 & DA-4X Deflection Circuits
DA-4X Horizontal Deflection Circuit
+12V
HDT T8002
4
B BOARD
R8123
3.5Vp-p
IC2801
Y/C
JUNGLE
4
HDR.
+135V
C8059 Q8023
2 2
3
7
2
R8125
CN508 CN8031
1818
6
1kVp-p
Q8024
1
Q8030
104Vp-p
R8119
CN2804 CN510
A BOARD
FROM
Q8039
H-CENT
HDT
T8003
D BOARD
+135V
10
Q8027
L8016
C8132
5
H-DY(B)
+
H-DY(R)
+5V
D8033
C8135
1
C8093
2
R8220
8
4
1
-5V
IC8009 3
H-CENT
PS8005
+
4
-
+
+
D8032
-5V
7
6
C8122
FROM IC8005/PIN 3
PWM & PINCUSHION
R8211
+
C8137
H-DY(G)
D8045
FIGURE 6-3 - DA-4X HORIZONTAL DEFLECTION
Horizontal Drive Circuit
C31P15-6-3 1529
11/8/02
(Reference Figure 6-3)
The circuit is split between an oscillator on the B-board and an output stage on the D-board. The 33.75KHz
horizontal oscillator is in the Y/C Jungle IC2801. IC2801/pin 4 outputs a 3Vpp rectangular waveform (H-DRV).
On the D-board, the H-DRV waveform is amplified through Q8030 and Q8023, and then applied to T8002/pin 7.
The horizontal output transistor Q8024 amplifies the signal to provide sufficient current to drive the HOT T8003
and the H-DY deflection yoke.
At the output stage, the HOT T8003 has two secondary windings that provide +/-15V for the Dynamic Focus
Q8007 and the Horizontal Centering circuit IC8009.
The waveforms shown on Figure 6-3 are the typical horizontal circuit signal shapes. The difference between this
set and a conventional set is the horizontal frequency, which is 33.75KHz as opposed to 15.75KHz in the
conventional set. The 33.75KHz is considered a high definition horizontal scan rate.
PWM Circuit
(Reference Figure 6-3)
The PWM circuit (Q8027) has two functions. First, it provides a regulated 102Vdc output for the horizontal
output transistor Q8024. Second, it compensates for horizontal pincushion affect and keeps the picture vertical
edges straight.
Regulator
The PWM circuit regulates +135Vdc from the power supply down to +102Vdc. Horizontal pulses from IC8005/
pin 10 (not shown in Figure 6-3) are used to drive Q8027 through IC8005pin 7 and output from IC8005/pin 3.
54
6. DA-4 & DA-4X Deflection Circuits
The pulses are amplified and output to the HOT T5001/pin 4. To control the output voltage, the horizontal output
is sampled (IC8005/pin 12) and used to change the pulse width of the H drive pulses. These changes regulate
the output voltage to +102Vdc at T5001/pin 4.
Pincushion Correction
If the PWM output voltage at T5001/pin 4 were changed, the horizontal picture size would vary accordingly. A
vertical pincushion signal is produced at IC2801/pin 11 (not shown) and is applied to the PWM circuit to increase
the picture width and compensate for the pincushion distortion.
The EW_PARA parabola signal form CN8025/pin 9 is first applied to IC8005/pin 6, which is used to drive the gate
of Q8027. The parabola signal at IC8025/pin 6 is compared to the H-DRV feedback waveform at IC8025/pin 7.
This comparison causes the PWM signal at the output IC8025/pin 3 to vary in pulse width. The change in pulse
width causes more or less voltage to be applied to the horizontal output Q5030 collector during the vertical scan
down the CRT. This varying voltage causes a varying current to be applied to the H-DY. Current is gradually
increased as the beam scans down until the current is at its maximum at the center of the CRT where the
pincushion distortion is the most extreme. The result is a straight-line (linear) scan down both sides of the CRT.
H-Centering Correction
Also shown in Figure 6-3 is the H-Centering circuit. This circuit applies a small positive and negative dc-offset to
the Red and Blue H-DY respectively, to keep the picture centered with reference to the Green H-DY on the CRT.
This function is performed dynamically through the service mode by varying the parabola waveform at CN8025/
pin 6 (HC_PARA), which is processed on the AD-Board, which produces the H-CENT signal at CN8027/pin 7.
The H-CENT is applied to IC8009/pin 1 and a dc-offsets is produced at IC8009/pin 4 through PS8005.
DA-4X Vertical Deflection Circuit
+15V
-15V
2
4
IC8003
V DRIVER
500mVpp
500mVpp
CN504
CN8025
VD(-) 18
VD(+) 19
CN510
IC2801
Y/C JUNGLE
CN2809
BOOST
28 28
4
4
27 27
3
3
VD(-) PB V OUT
1
R8013
R8014
3
5
R8018
VD(+)
6
7
D8004
+15V
D8002
16V
R8147
R8041
R8032
B BOARD
54Vpp
V-PROT
V-DY(B)
A BOARD
V-DY(R)
D BOARD
R8002
FIGURE 6-4 - DA-4X VERTICAL DEFLECTION CIRCUIT
V-DY(G)
C31P15-6-4
10/7/02
Vertical Drive
(Reference Figure 6-4)
The vertical oscillator inside IC2801 starts and outputs ramp signals at IC2801/pin 18 (VD (-)) and IC2801/pin 19
(VD (+)) when power is applied. Data need not be present for vertical drive to output from IC2801.
The vertical stage has not changed functionally from previous models. The vertical drive signals from IC2801/
pins 18 and 19 are applied to IC8003/pins 1 and 7. The ramp signals are amplified in IC8003 and the output drive
for the V-DY is output at IC8003/pin 5.
55
7. DA-4 & DA-4X Data Communication Bus Networks
Chapter 7 - DA-4 & DA-4X Data Communication Bus Networks
There are three data communications networks used in the DA-4 and DA-4X chassis’s. All three consist of data
and clock lines, which communicate with multiple ICs. Refer to Table 7-1.
Table 7-1 - Data Communications Bus Networks
Network
Location
Purpose
SDAT, SCLK
IC2300/pins
Micro
31,28
Main Overall System Control
BDAT, BCLK
IC2300/pins
Micro
30,29
Main NVM1 (IC2302) Control
DO, CO
IC3090/pins
Micro
95,97
MID MID Processing Control
DA-4 and DA-4X Data Communications Diagram
IC2300
MAIN MICRO
BDAT
BCLK
M BOARD
IC2302
NVM
U BOARD
CN2006 CN1502
DATA
B12 B12
DATA
A13 A13
IC2004
YCT
MAIN
IC2006
COMP. I/F
IC2005
YCT
SUB
IC2304
SUB CCD &
V CHIP
IC2303
MAIN CCD &
V CHIP
CN2302
20 18
20 18
IC2200
3D
COMB
12 14
12 14
CN525
IC2504
AUDIO
PROC.
IC1502
A/V
SWITCH
CN2302
CN525
CN507
11
4
CN513
2
4
CN3203
IC3400
MID
IC3090
MID
MICRO
IC3003
A/D DNR
IC8601
A/D
IC2801
CRT
DRIVE
CLK
2
A BOARD
10
TEST
CONNECTOR
B23 B22
IC3089
NVM
B23 B22
B BOARD
MIS BOARD
IC3303
DRC
DATA
DATA
TU502
CLK
TU501
IC903
DY-CONN
CN3601
CN104
IC121
IC
SOCKET
FIGURE 7-1 - DA-4 & DA-4X DATA COMMUNIATIONS DIAGRAM
56
C31P15-7-1
10/7/02
7. DA-4 & DA-4X Data Communication Bus Networks
(Reference Figure 7-1)
Main Micro IC2300 generates the clock signal for communications bus network SDAT, SCLK and BDAT, BCLK.
Bus network SDAT, SCLK is used to send data to most of the ICs in the TV set.
Network BDAT, BCLK is dedicated communications to the NVM IC2302 on the M-board.
At power ON, the user and deflection data in IC2302 is retrieved by IC2300 using network BDAT, BCLK and
passed to the appropriate ICs. Once the ICs receive this data to set their operating parameters, the TV can
function.
The data on both bus networks is always present as long as the TV is ON. The data signals can viewed at
CN525/pins 20 and 18 (SDAT and SCLK), and CN525/pins 14 and 12 (BDAT and BCLK). The digital signal for
all four data looks the same when probing with an oscilloscope (5Vpp digital signal). Reference Waveform 7-1
for the oscilloscope display waveform.
CH2
2v
10ms
Waveform 7-1
SDAT_SCLK_BDAT_BCLK
Communications bus network DO, CO is only used between the three MID ICs IC3090 (MID Micro), IC3400 (MID
IC), and IC3089 (NVM). MID Micro IC3090 communicates with MID IC3400 to retrieve processed data such as
the input horizontal frequency and uses it to select video signal paths.
MID Micro IC3090 also communicates with memory IC3089 to set up the multi-picture parameters.
57
8. DA-4 & DA-4X Audio Circuits
Chapter 8 - DA-4 & DA-4X Audio Circuits
DA-4 and DA-4X Audio Block Diagram
FROM HB
J1501 BOARD J1501 J1501 J1501 CN2006 CN2006
A1LR A2LR A3LR A4LR A7LR TU1LR TU2LR
IC1502
AV SWITCH
MONITOR
AUDIO (L R)
Q1503,
Q1504
J1509
A5LR
AUDIO OUT
J1502
VAR./FIX LR
J1508
A6LR
MAIN
AUDIO (L R)
U-BOARD
CN1502 B25 A25
CN2006 B25 A25
B5 A5
B5 A5
B3 A3
B3 A3
B1 A1
B1 A1
VAR/FIX
(L R)
MONITOR OUT
J1502
IC2501
AUDIO PROCESSOR
MAIN
AUDIO (L R)
SUB WOOFER
AUDIO
(WL, WR)
CN2002 2
CN523 2
A MUTE
FROM
IC2300
M-BOARD
4
4
M-BOARD
6
6
7
7
Q515,
Q516
Q518,
Q519
DA-4 ONLY
2
PS501
24V
IC2502
BUFFER
4
R
9
2
L
IC1509 AMP
R
L
12
PS502
24V
7
4
WR
WL
9 IC1508 AMP
WR
WL
12
A MUTE
FROM
IC2300
M-BOARD
A-BOARD
7
3
7
1
5 CN527
TO SPEAKERS & WOOFER
FIGURE 8-1 - DA-4 AND DA-4X AUDIO BLOCK
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C31P15-8-1 1530
11/4/02
8. DA-4 & DA-4X Audio Circuits
(Reference Figure 8-1)
IC1502 is an Audio/Video Switch (located on the U-board), which selects both audio and video using the I2C bus
from Main Micro IC2300 (not shown). The following audio inputs are available to IC1502:
• Audio 1 – 4
•
Audio 7
•
TU1 & 2
The selected audio is then sent to the M-board through CN1502/pins B25 & A25 (U-board) and CN2006/pins B25
& A25 (M-board), and applied to the audio processor IC2501. Audio inputs 5 & 6 from the U-board are applied
directly to the audio processor IC2501 (U-board) through CN1502/pins B5, A5, B3 and A3 (U-Board), and CN2006/
pins B5, A5, B3 and A3 (U-Board).
The Monitor L/R output also is output from the AV Switch IC1502, applied to Q1504 (buffer) and Q1503 (buffer),
and then to J1503.
The audio processor IC2501 takes the main audio input and produces a main L/R output and sub-woofer WL/
WR output (IC2501 also produces the Steady Sound feature). These outputs are then passed to the A-board
through CN2002/pins 2, 4, 6 and 7 (M-board) and CN523/pins 2, 4, 6 and 7 (A-board). Next they are applied to
the audio amplifies IC509/pins 2 & 4 (Midrange) and IC1508/pins 2 and 4 (Woofer). Note: IC508 is not used in
the DA-4X chassis (projection set). The low frequencies are enhanced in the protection set used the
DAC Speaker System. The DAC system uses the Midrange speakers TV cabinet as a low frequency
chamber system.
The VAR/FIX L/R audio is output from Audio Processor IC2501. Audio passes through buffer IC2502 and then
to CN2006/pins B1 and A1 (M-board), CN1502/pins B1 and A1, and is finally output at J1502.
Speaker outputs can be viewed at CN527/pins 3, 7, 1 and 5.
Mute transistor Q515, 516, 518 and 519 are activated when the MUTE or Channel buttons are pressed on the
remote controller (audio is mute between channels when changing channels). The A-MUTE line will go High,
and the transistor will turn ON and send the audio to ground muting the audio output.
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C31P15112
©2002 Sony Electronics Inc.
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Reproduction in whole or part without written permission is prohibited. All rights reserved
11/15/02