Download PHOTOFACT, Technical Service Data

PHOTOFACT,
Technical Service Data
SONY
INDEX
Model W-27EXR25 (Chassis SCC-D50F-A)
Adjustment and Alignment Tools .... 1
Convergence Adjustments . . . . . . . . . . 6
GridTrace Location Guide
ABoard . . . . . . . . . . . . . . . . . . . . .8
..9
GBoard . . . . . . . . . . . . . . . . . . . . .9
.8
PBoard-TopBoard . . . . . . . .8 . . .
UlBoard
.9
................... .9
Important Parts Information ........ 10
Miscellaneous Adjustments ......... 6
PartsList . . . . . . . . . . . . . . . . . 9,10,11
Photos
ABoard . . . . . . . . . . . . . . . . . . .7,8
CBoard . . . . . . . . . . . . . . . . . . . . .9
Cabinet - Rear View ........... 1
CRT Neck Assembly . . . . . . . . . . 6
GBoard . . . . . . . . . . . . . . . . . . . . .9
HBoard . . . . . . . . . . . . . . . . . . . . .8
PBoard-BottomBoard . . . . . .7,8
PBoard-TopBoard . . . . . . . . .7,8
Ul Board ................. .4,9
U2Board . . . . . . . . . . . . . . . . . .8,9
! Troubleshooting Quick-Checks
ABoard . . . . . . . . . . . . . . . . . . . . .7
CBoard . . . . . . . . . . . . . . . . . . . . .9
PIP Adjustments . . . . . . . . . . . . . . . . . . 6
Placement Chart ................. .5
Safety Precautions . . . . . . . . . . . . . . . 1
Safety Related Adjustments ......... 6
Schematics
CRT ....................... .2
Control . . . . . . . . . . . . . . . . . . . . . . .
D/A Converter . . . . . . . . . . . . . . . . 2
MTS Decoder ............... .3
PIP . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Power Supply ................ .4
Television ................... .2
Terminal Guides and Notes ........ .7
Test Equipment . . . . . . . . . . . . . . . . . . . 1
Troubleshooting ................... 1
Tuner Terminal Guide ............. 6
Tuner Voltage Chart . . . . . . . . . . . . . . . 6
For Supplier Address,
See PHOTOFACT Annual Index
Complete coverage
for servicing a television receiver...
l
l
Schematics
Component
locations
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Parts lists
Troubleshooting
guide
Coverage includes this additional model and chassis:
MODEL
KV-27EXR20
CHASSIS
SCC-DSOE-A
HOWARD W. SAMS & COMPANY
DECEMBER 1991 SET 2910
TROUBLESHOOTING
POWER SUPPLY
HORIZONTAL
Check AC Fuse F60 1.
Determine if the TV is in shutdown:
If F60 1 is open:
Check Bridge Rectifier Diodes (D601, and D602), Resistor
(R601), Capacitors. C601, C603 thru C606, Electrolytics C607,
and C650, Power Converter IC (IC65 l), and Power Transformer
(T604).
Apply 120V and check for 17.OV at the (+) lead of D602.
If 17.OV is missing:
Check Line Filters (T601, T602), Power Transformer (T604),
Capacitors C608, C609, Electrolytic C610, and D602.
If 17.OV is present, check for 15OV* at the (+) lead of D601.
If 15OV* is missing:
Check the voltages, waveforms, and components associated
with Power Relay (RY601), and Relay Driver Transistor
(Q601), and D601.
Note: The set may be in shutdown. Refer to the “High Voltage
Shutdown” section of this Troubleshooting guide.
If 15OV* is present at the (+) lead of D601, check for the proper waveform at pin 1 of IC65 1.
If the waveform is missing:
Check the voltages, waveforms, and components associated
with IC65 1, Transfer IC (IC652), Converter Transformer
(T651), and Soft Start Transistor (4612).
If the proper waveform is present at pin 1 of IC65 1:
Check the voltages, waveforms, and components associated
with T6.5 1.
* Taken from isolated ground.
HIGH VOLTAGE SHUTDOWN
The
high voltage is monitored by Diode D531, rectifying pulses
from the Horizontal Output Transformer (T500). Should the high
,voltage increase, the rectified voltage at the cathode of Diode D531
will also increase, This will cause the voltage at pin 8 of Protect
Module (PM501) to increase and turn on Protect Transistors (Q607,
4608) which causes Relay Drive Transistor (4601) to turn off and
remove power from the set.
To troubleshoot, remove Resistor R629 fom the circuit. Use a variac
for AC power. Start at 90VAC and increase as necessary to locate
and repair the defect. Return R629 to the circuit.
Note: Care should be taken in defeating the high voltage shutdown
circuit, as this may cause excessive X-radiation and damage the
CRT, TSOO, and associated components. Monitor the high voltage
and troubleshoot.
Refer to the “High Voltage Shutdown” section of this
Troubleshooting guide.
If the TV is not in shutdown, inject a horizontal signal at the base of
the Horizontal Output Transistor (4502).
If horizontal deflection is now present:
Check the voltages, waveforms, and components associated
with pins 37,39,41, and 45 of Y/C/J IC (IC301), and
Horizontal Drive Transistor (Q501).
If there is no horizontal sweep:
Check the voltages, waveforms, and components associated
with 4502, and Horizontal Output Transformer (T500), and
check components associated with Diodes D5 17, D5 19, D520,
D521, and D531 for defects.
The high voltage rectifier is part of T500 and if defective will effect
the performance of the horizontal circuits.
If the horizontal oscillator is off frequency:
Check the voltages, waveforms, and components associated
with AFC-DET Transistor (Q307), and Buffer Transistor
(Q3W.
Horizontal linearity or foldover problems may be caused by Capacitors C506, C507, and C509 beiig defective.
VERTICAL
Inject a vertical drive signal at pin 3 1 of Y/C/J IC (IC301).
If vertical deflection is now present:
Check the voltages, waveforms, and components associated
with pins 29 thrn 34,38, and 44 of IC301.
If there is still no vertical deflection:
Check the voltages, waveforms, and components associated
with Vert Out IC (ICSOO).
Vertical linearity or foldover problems may be caused by pincushion, vertical feedback and bias circuits:
Check the voltages, waveforms, and components associated
with Pin Correction IC (IC531) and Pin Out Transistor (4530).
Also check Electrolytics C328, C538, C540, C562, C563, and
C566 for defects.
IF-AGC
Inject a video signal at the IF input and check for video on the CRT.
If video is present:
Check the tuner, tuner control, and tuner AFC circuits.
TROUBLESHOOTING
If there is no video on the CRT, check for a video waveform at
TP12.
If video is present at TP12:
Refer to the “Video” section of this Troubleshooting guide.
continued
Check the voltages, waveforms, and components associated
with pins 3,4,8,26, and 27 of Y/C/J IC (IC301), Buffer
Transistors (43 lO,Q3 13), Gamma Comp 1 Transistor (43 15),
and Equalizer Transistor (43 14). Y Clamp Transistor (43 17),
and Gamma Comp 2 Transistor (4316).
If brightness is inadequate or camrot be controll&
If there is no video at TP12:
Check the voltages, waveforms, and components associated
with IF Module (IF201), and AGC Mute Transistor (Q102).
A defective AGC circuit can cause an overloaded picture, excessive
snow or loss of audio and video.
See the AGC Voltage Chart for AGC voltages with signal.
AGC Voltage Chart
IF201
pm 1 5.3v
Check the voltages, waveforms, and components associated
with pin 5 of v901.
CHROMA
Check for a chroma waveform at pm 5 of Y/C/J IC (X301).
If the waveform is missing:
Check the voltages, waveforms, and components associated
with Buffer Transistor (Q417), C-Switch IC (IC403), and pin 4
of Comb Filter (CM1301).
SYNC
If chroma waveform is present at pin 5 of IC30 1, cheek for the pmp
er waveforms at pins 20,22,24 of IC301.
If there is no vertical or horizontal sync:
If these waveforms are missing:
Check the voltages, waveforms, and components associated
with Y Buffer Transistor (4301).
If there is no vertical sync:
Check the voltages, waveforms, and components associated
with pins 38, and 44 of Y/C/J IC (IC301), V/Sext 1 Transistor
(Q302), V/Sext 2 Transitor (Q303), and V/Sext 3 Transistor
Check the voltages, waveforms, and components associated
with pins 5,6,7,19 thru 25 of IC301.
Check the 3.58MHz oscillator at pin 7 of IC301.
If the proper wavforms are present at pins 20,22,24 of IC301:
Refer to the “Raster” section of this Troubleshooting guide.
(Q3W.
If there is no horizontal sync:
Check the voltages, waveforms, and components associated
with pins 41, and 45 of IC301.
VIDEO
Inject a signal at TP12, and check for video on the CRT
If video is present:
Refer to the “IF-AGC” section of this Troubleshooting guide.
If there is no video on the CRT, check for a video waveform at pin 6
of Comb Filter (CM1301).
If video is missing at pm 6 of CM1301:
Check the voltages, waveforms, and components associated
with Buffer Transistors (4409, Q410), and AV-Switch IC
(IC444), and CM1301.
If video is present at pin 6 of CM1301, check for a video waveform
at the emitter of Y Amp Transistor (4305).
If the video is missing:
Check the voltages, waveforms, and components associated
with 4305, Buffer Transistor (Q416), and Y Switch IC (IC402).
If the waveform is present at the emitter of 4305:
RASTER
Check the CRT and CRT voltages. Cheek the voltages, waveforms,
and components associated with Buffer Transistor (Q711), SW 1
Transistor (Q710), and SW 2 Transistor (4712).
If there is no Red:
Cheek the voltages, waveforms, and components associated
with pin 20 of Y/C/J IC (IC301), Red Output Transistor (4708).
Video Amp Transistor (Q709), and Red 1K Det Transistors
(Q707,Q7 16).
If there is no Green:
Check the voltages, waveforms, and components associated
with pin 22 of IC301, Green Output Transistor (Q704), Video
Amp Transistor (Q705), and Green 1K Det Transistors (4706,
47 15).
If there is no Blue:
Check the voltages, waveforms, and components associated
with pm 24 of IC301, Blue Output Transistor (Q701), Video
Amp Transistor (Q702), and Blue 1K Det Transistors (4703,
47 14).
If the raster has a keystone shape:
Check the Deflection Yoke (L550).
SET 2910 Page 1
TROUBLESHOOTING
If the raster has height or width problems:
Refer to “Vertical”, “Horizontal”, and “Power Supply” sections
of this Troubleshooting guide.
continued
Check the voltages, wavefotms, and components associated
with pins 10 thru 13 of IC2104, Vertical Pulse Transistor
(Q2119), and pins 5 and 36 of Y/C/J IC (IC2103).
If waveform is present at pin 23 of IC2204, check for the proper waveform at pin 61 of IC2204.
AUDIO
Select an active TV channel and check for an audio waveforms at
pins 1 and 2 of MTS Decode IC (IC25 1).
If there is no audio:
Check the voltages, waveforms, and components associated
with IC25 1, and pin 10 of IF Module (IF201).
If audio waveforms are present at pins 1 and 2 of IC251, cheek for
audio waveforms at pins 1 and 5 of Audio Amp IC (IC405).
If waveform is missing:
Check the voltages, waveforms, and components associated
with pins 1 and 2 of IC2 104, and Buffer Transistor (43 12)
If waveform is present at pin 23 of IC2204:
Check the voltages, waveforms, and components associated
with IC2204.
PIP SYNC
If audio waveforms are missing:
Check the voltages, waveforms, and components associated
with Audio Buffer Transistors (4430, Q431), and Buffer
Transistors (4202,Q203).
If audio waveforms are present at pins 1 and 5 of IC405:
Check the voltages, waveforms, and components associated
with IC405, Audio Mute Transistors (4432, Q433), and Mute
Transistor (Q 103).
If there is no vertical or horizontal sync:
Check the voltages, waveforms, and components associated
with V Buffer 3 Transistor (Q2125), and Buffer Transistor
(42130).
If there is no vertical sync:
Check the voltages, waveforms, and components associated
with pm 5 of Y/C/J IC (IC2103).
If there is no horizontal sync:
PIP HORIZONTAL
Check the voltages, waveforms, and components associated
with pin 4 of IC2103.
Check for the proper waveforms at pin 9 of A/D Conv IC (IC2206),
and pin 24 of PIP Control IC (IC2204).
If the waveforms are missing:
Check the voltages, waveforms, and components associated
with pins 4,6 thru 10, and 28 of Y/C/J IC (IC2103), pins 8 and
9 of IC2 104, Horizontal Pulse Transistor (42 120), Horizontal
Out Transistor (4212 l), and Horizontal Drive Transistor
(42122).
If waveforms are present, cheek for the proper waveform at pin 60 of
IC2204.
If waveform at pin 60 of IC2204 is missing:
Check the voltages, waveforms, and components associated
with Horizontal Width IC (IC2 102), Horizontal Pulse Transistor
(Q2117), and pin 39 of Y/C/J IC (IC301).
If waveform at pin 60 of IC2204 is present:
Check the voltages, waveforms, and components associated
with IC2204, and IC2206.
PIP VIDEO
Check for the proper waveform at pin 34 of Y/C/J IC (IC2103).
If video is missing at pin 34 of IC2 103:
Cheek the voltages, waveforms, and components associated
with V Buffer 1 Transistor (Q2245), V Buffer 2 Transistor
(Q2123), Buffer Transistor (Q413), and AV-SW IC (IC444).
If video is present at pin 34 of IC2103, check for a video waveform
at pin 16 of A/D Conv IC (IC2206).
If the waveform is missing:
Check the voltages, waveforms, and components associated
with Y Out Transistor (Q2139), Y Buffer 2 Transistor (Q2102),
Y Amp Transistor (42 10 l), Y Buffer 1 Transistor (42 116), and
pins 14,21,23,25,30,32,33, of Y/C/J IC (IC2103).
If waveform is present at pin 16 of IC2206, check for the proper waveform at pm 4 of Y D/A Conv IC (IC2201).
If the waveform is missing at at pin 4 of IC2201:
PIP VERTICAL
Check for the proper waveform at pin 23 of PIP Cont IC (IC2204).
If the waveform is missing:
Check the voltages, waveforms, and components associated
with IC2201, pins 1,46 thru 5 1, and 54 of IC2204.
Cheek for the proper waveform at the emitter of YS Buffer Transmitter (42244).
TROUBLESHOOTING
continued
If the wave form is missing at the emitter of 42244:
Check the voltages, waveforms, and components associated
with 42244, pins 3 thru 6 of IC2 104, and pin 3 1 of IC2204.
If the waveform is present at pin 4 of IC2201:
Check the voltages, waveforms, and components associated
with Y Buffer Transistor (42202).
PIP CHROMA
Check for the waveforms at pins 20 and 22 of\Y/C/J IC (IC2103).
If the waveforms are missing:
Check the voltages, waveforms, and components associated
with pins 16 thru 22, and 31 of IC2 103.
Check the 3.58MHz oscillator at pins 15 and 18 of IC2103.
Check the voltages and components associated with Sub Color
Control and pin 13 of IC2103.
Check the voltages and components associated with Sub Hue
Control and pin 12 of IC2103.
If chroma waveform is present at pins 20 and 22 of IC2103, check
for the proper waveforms at pins 17 and 18 of A/D Conv IC
(IC2206).
If the waveforms are missing at pins 17 and 18 of IC2206:
Check the voltages, waveforms, and components associated
with R-Y Out Transistor (Q2103), and B-Y Out Transistor
(42114).
If the waveforms are present at pins 17 and 18 of IC2206, check for
the proper waveforms at pins 4 of R-Y D/A Conv IC (IC2202), and
B-Y D/A Conv IC (IC2203).
If the waveforms am missing at pin 4 of IC2202, and IC2203:
Check the voltages, waveforms, and components associated
with IC2202, IC2203, PINP Conv IC (IC2204), and IC2206.
If the waveforms are present at pin 4 of IC2202, and IC2203:
Check the voltages, waveforms, and components associated
with R-Y Buffer Transistor (Q2203), B-Y Buffer Transistor
(Q2204), Red Drive Transistor (Q2106), Blue Drive Transistor
(Q2107), and Green Drive Transistor (42109).
SET 2910 Page 1
MISCELLANEOUS ADJUSTMENTS
PRETUNING
Note: Use Remote Commander to accomplish prehming. All procedures require an antenna or cable connected, and power supplied to
the set.
3. Make changes on selected adjustment by pressing the 3 and
6 button.
Saving Adjustments to Memory
1. Adjustments must be saved to memory.
Auto Memory
2. To save adjustment, press the Mute button and then the
Enter button.
1. Press the Auto Program button.
Add Channel
Memory Write Confirmation
1. Disconnect AC plug from outlet.
1. Select Channel.
2. Plug set in and enter Service Adjustment Mode.
2. Press Add button.
3. Select adjustment and confirm that setting was saved to
memory.
3. Repeat steps one and two to add other channels.
Delete Channel
Exiting Service Adjustment Mode
1. Select Channel.
1. Turn set off and then back on.
2. Press Erase button.
3. Repeat steps one and two to erase other channels.
Adjustments Required When Replacing IC’s
IC102: VSOM, AFC, REF, ROFF, GOFF, BOFF, ABLM,
TEST, DRGB.
Guide Function
1. Press the Guide button to select Tie, Timer, and Channel
Block.
IC251: MPX, FILO, DEEM, STEV, SAPV, PILO, SEP, VD,
LVOL, RVOL.
2. Select function by pressing guide button until desired
function is highlighted. Press Enter button.
IClOl: DISP
IC301: HFRE, VFRE, VPOS, VSIV, VLIN, VSCO, HPOS,
HSIZ, PAMP, CPIN, PPHA, VCOM, GAMP, BAMP,
GCUT, BCUT, CROM, SPIX, SHUE, SCOL, SBRT, RGBP,
VSOM, AFC, REF, ROFF, GOFF, BOFF, ABLM.
3. Follow the displayed instructions.
Sleep
1. Press Sleep button. The set will turn off automatically in
approximately one hour.
2. To cancel sleep timer, press Sleep button until Sleep Off is
indicated or turn set off.
Note: This set employs digital customer controls. Use the Remote
Commander to accomplish digital adjustments. Unless specified all
adjustments are accomplished with controls in reset position.
VSMO, AFC, REF, ROFF, GOFF, BOFF, ABLM, TEST,
DRGB
The
following adjustments have the listed initial settings. Save each
adjustment to memory before performing the next one. Enter the
Service Adjustment Mode. Adjust the level of VSOM to 00, AFC to
00, REF to 02, ROFF to 01, GOFF to 01, BOFF to 01, ABLM to 01,
TEST to 00, DRGB to 01.
DIGITAL ADJUSTMENT PROCEDURES
Entering Service Adjustment Mode
1. Tune in a picture, and turn set off.
2. Insert a small tuning tool in service mode access hole,
located to the left of the right speaker connections on the
back of the set. While depressing Service Button (SW900),
turn set on.
Making Adjustments
1. Enter service mode.
2. Select adjustment by pressing the the 1 and 4 buttons.
DISPLAY POSlTlON (DISP)
Enter the Service Adjustment Mode. Select DISP adjustment. Adjust
the level to center the display 2 l/2 inches on either side. Save adjustment to memory.
HORIZONTAL FREQUENCY (HFRE)
Tune in a colorbar pattern. Enter the Service Adjustment Mode. Select the AFC Adjustment and set the AFC to 03. Horizontal will lose
sync. Select HFRE adjustment. Adjust the level until the picture
locks in. Save adjustment to memory. Select AFC adjustment and set
level to 00. Save adjustment to memory.
Page 6 SET 2910
PIP ADJUSTMENTS
Note: Adjustments made with PIP on. Refer to “Digital Adjustment
Procedure” in Miscellaneous Adjustment Section.
PIP BRIGHTNESS AND CONTRAST
Tune in a picture. Set Brightness, Color, and Picture to MINIMUM.
Adjust Bright Level Control (RV2 105) for just visible highlights. Set
Picture and Brightness to Maximum and adjust Contrast (RV2108)
for minimum blooming. Set Picture, Brightness, and Color to reset.
PIP WINDOW POSITION
Tune in a picture. Place PIP window in upper left comer of semen.
Adjust Position Control (RV2103) to place PIP window 1 inch from
left side of screen. Place PIP window in lower right comer of screen.
Adjust Position Control (RV2103) to place PIP window 1 inch from
right side of screen.
PIP SUB COLOR/SUB TINT
Tune in a colorbar pattern on the PIP screen. On main screen select a
video input with no signal. Position PIP screen in lower left comer
of screen. Connect an oscilloscope to TP47B. Adjust Sub Color Control (RV2 107) so that the PIP portion of the signal is 1.9V p-p. Tune
in a picture on PIP window. Adjust Sub Hue Control (RV2106) to
obtain proper skin tones.
PIP RGB PICTURE (RGBP)
Tune in a colorbar Pattern. Enter Service Adjustment Mode. Select
RGBP adjustment, and adjust level to 00. Set Picture and Brightness
to MINIMUM. Adjust RGBP for proper colorbars in PIP window.
Save adjustment to memory.
PIP B-Y
Tune in a colorbar pattern. Turn B-Y Control (RV2200) clockwise
until PIP window turns solid blue and note position. Turn RV2200
counterclockvise until PIP window colorbars lose blue and note
position. Set RV2200 to midpoint between the two positions.
PIP R-Y
Tune in a colorbar pattern. Turn R-Y Control (RV2201) counterclockwise until PIP window turns solid red and note position. Turn
RV2201 clockwise until PIP window colorbars lose red and note
position. Set RV2201 to midpoint between the two positions.
SUB PICTURE
Tune in a colorbar pattern on the PIP window. Adjust LC Networks
(PL2205, PL2206) so that the PIP window size and location is identical in all positions.
MISCELLANEOUS ADJUSTMENTS
continued
HORIZONTAL SIZE (HSIZ)
VERTICAL COMP (VCOM)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Select HSIZ, and adjust level for slight horizontal overscan. Save adjustment to memory.
Enter the Service Adjustment Mode. Select VCOM, and adjust level
to 02. Save adjustment to memory.
HORIZONTAL CENTER (HPOS)
Perform Horizontal Frequency Adjustment. Tune in a crosshatch pattern. Adjust Horizontal Centering Connector (A-55) for best horizontal centering. Enter the Service Adjustment Mode. Select HPOS, and
adjust level for best horizontal centering. Save adjustment to
memory.
CHROMA TRAP (CROM)
Tune in a colorbar pattern. Set Color to Maximum, and turn NOTCH
on. Connect an oscilloscope to TP47R (On C-Board). Enter the Service Adjustment Mode. Select CROM, and adjust level for MINIMUM chroma. Save adjustment to memory.
SUB BRIGHTNESS (SBRT)
PINCUSHION (PAMP, CPIN, PPHA)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Select PAMP, and adjust level for straight vertical lines at left and
right of screen. Save adjustment to memory. Select CPIN, and adjust
level for straight vertical lines at top and bottom of screen. Save adjustment to memory. Select PPHA, and adjust level for equal spacing
of vertical lines from top to bottom of screen. Save adjustment to
memory.
VERTICAL FREQUENCY (VFRE)
Tune in a colorbar pattern. Enter the Service Adjustment Mode. Select VFRE adjustment, and adjust the level until the picture locks in.
Save adjustment to memory.
VERTICAL SIZE (VW)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Select VSIZ, and adjust level for slight vertical overscan. Save adjustment to memory.
Tune in a crosshatch pattern. Set Picture and Brightness to MINIMUM. Enter the Service Adjustment Mode. Select SBRT, and adjust
level for visible highlights. Save adjustment to memory.
SUB CONTRAST (SPIX)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Select SPIX, and adjust level for best picture. Check tracking by adjusting Picture and Brightness to MINIMUM and Maximum and
check for blooming. Readjust if necessary. Save adjustment to
memory.
SUB HUE AND SUB COLOR (SHUE, SCOL)
Tune in a colorbar pattern. Connect an oscilloscope to TP47B (On
C-Board). Enter the Service Adjustment Mode. Select SCOL, and
adjust level for 3.W p-p. Tune in an active channel. Select SHUE,
and adjust level for proper skin tones. Save adjustment to memory.
S - CORRECTION (VSCO)
VERTICAL POSITION (VPOS)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode:
Select VPOS, and adjust level to center picture vertically. Save adjustment to memory.
VERTICAL LINEARITY (VLIN)
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Select VLIN, and adjust level for equal vertical spacing of pattern.
Save adjustment to memory.
Enter the Service Adjustment Mode. Select VSCO, and adjust level
to 0. Save adjustment to memory.
COLOR PURITY
Use a degaussing coil to demagnetize the CRT and mounting brackets. Enter the Service Adjustment Mode. Adjust ROFF and BOFF
levels to MINIMUM. Adjust GOFF for a green raster. Loosen
Deflection Yoke clamp screw and slide it backward to obtain a vertical green band. Adjust purity rings to center the vertical green band.
Slide the Deflection Yoke forward until a uniform green screen is
obtained. Check Blue and Red purity by adjusting the ROFF, GOFF,
and BOFF levels. Return all controls and adjustments to normal levels.
S E T 2910, P a g e 6
MISCELLANEOUS ADJUSTMENTS
COLOR TEMPERATURE @CUT, GCUT, GAMP, BAMP)
Adjust G2 Control (RV701) so that the retrace lines just disappear.
Tune in a crosshatch pattern. Enter the Service Adjustment Mode.
Set Picture to MINIMUM. Select SBRT adjustment, and adjust level
for MINIMUM. Select GCUT and BCUT adjustments and adjust levels for best white balance. Save adjustment to memory. Set Picture
to Maximum. Select GAMP and BAMP adjustments and adjust levels for best white balance. Save adjustment to memory. Perform Sub
Brightness Adjustment.
CONVERGENCE
Adjust the Focus, Horizontal Size, Vertical Size, and Vertical Liiearity. Tune in a dot pattern. Adjust the Horizontal Static Control
continued
(RV702) to converge the Red and Blue dots over the Green dots
horizontally at the center of the screen. Rotate the Vertical Static
Magnets to converge the Red and Blue dots over the Green dots vertically at the center of the screen. NOTE: Some versions use a BMC
magnet. To adjust the BMC magnet, slide it in and out to correct for
insufficient horizontal static convergence, rotate the BMC magnet to
correct for insufficient vertical static convergence. Tune in a crosshatch pattern and loosen the Delection Yoke (L550) screw. Remove
the rubber wedges between the Deflection Yoke and the CRT. Tilt
the Deflection Yoke up or down to converge the vertical lines at top
and bottom of screen and the horizontal lines at the right and left
sides of the screen. Tilt the Deflection Yoke right or left to converge
the vertical lines at the right and left sides of the screen and the horizontal lines at the top and bottom of the screen. Repeat convergence
procedure if necessary to obtain best overall convergence. Apply
adhesive to wedges and carefully replace on CRT.
CRT NECK ASSEMBLY
- PURITY MAGNET
,V STAT MAGNET
WC MAGNET
SAFETY RELATED ADJUSTMENTS
R559 CONFIRMATION METHOD (HOLD-DOWN
CONFIRMATION) AND READJUSTMENTS
2. Confum that the voltage at TP-85 is more than 108V when
the set is operating normally with 120VAC supply.
The
following adjustments should always be performed when replacing the following components PMSOl, 4608, 4607, R629, R628,
R627, R559.
Hold-down Operation Confirmation
1. Turn the Power switch on, and receive a white screen.
Adjust ABL current to 1650 +/- 8OuA with Picture and
Bright controls.
Preparation Before Confirmation.
1. Remove R675 on the G board and connect a variable
resistor (RVl about 10K) between pin 1 of IC653 and B+
line.
2. Supply 12OVAC +/- 2.0VAC with variable transformer.
Hold-down Operation Confirmation
1. Turn the Power switch on, and receive a white signal.
Adjust ABL current to 1650 +/- 80uA with Picture and
Bright controls.
2. Increase B+ line voltage gradually by adjusting the
resistance of RVl . Confirm that the MINIMUM voltage is
less than 143SV when the raster disappears during
operation of the hold-down circuit.
Note: When the holddown circuit starts operating, turn the
set off immediately.
3. Turn the Power switch on, and receive a dot pattern. Adjust
ABL current to 150 +/- 50uA with Picture and Bright
controls.
4. Increase B+ line voltage gradually by adjusting RVl.
Confvm that the MINIMUM voltage is less than 146.W
when the raster disappears during operation of hold-down
circuit.
Note: When the hold-down circuit starts operating, turn the
set off immediately.
2. Gradually apply DC voltage to TP-85, and confirm that the
voltage is less than 137.5V when raster disappears during
operation of the hold-down circuit.
Note: When the hold-down circuit starts operating, turn the
set off immediately.
3. Turn the Power switch on, and receive a dot pattern. Adjust
ABL current to 150 +/- 5OuA with Picture and Bright
controls.
4. Gradually apply DC voltage to TF-85, and confirm that the
voltage is less than 138.5V when raster disappears during
operation of the hold-down circuit.
Note: When the hold-down circuit starts operating, turn the
set off immediately.
Holddown Readjustment
1. If Hold-down Operation Confiition cannot be satisfied,
readjustment should be performed by altering the resistance
value of R570.
B+ VOLTAGE CONFIRMATION
The following adjustment should always be performed when replacing IC653 and R675.
1. Supply 130VAC +/- 1VAC with variable auto-transformer.
Holddown Readjustment
1. If Hold-down Operation Confirmation cannot be satisfied,
readjustment should be performed by altering the resistance
value of R559.
2. Receive a monoscope signal.
3. Set Picture and Bright controls to initial reset position.
4. Confii that the voltage at TP-91 is less than 137V.
5. If step 4 cannot be satisfied, replace IC653 and R675.
Repeat above steps.
R570 CONFIRMATION METHOD (HOLD-DOWN
CONFIRMATION) AND READJUSTMENTS
The following adjustments should always be performed when replacing the following components IC653, PM501, 4608, 4607, D531,
C545, C627, R570, R591, R627, R628, R675, T500
Preparation Before Confirmation.
1. Turn the Power switch on, and receive a white signal. Set
the Picture and Bright controls to Maximum.
Courtesy of
Manufacturer