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FIND OUT WHY THE A1 +5 VD LED IS NOT ON STEADILY
If the +5 VD LED is not on steadily, the +5 VD line voltage is missing or is not enough
to power the analyzer. The problem may be in the A40 pre-regulator, the A50 DC-DC
Converter, the A1 CPU, and any of assemblies obtaining the power from +5 VD supply.
1. Check the A40 Pre-Regulator
a.
b.
c.
d.
Turn the analyzer power o.
Disconnect a cable form the A50J1. The A50J1 location is shown in Figure 7-6.
Turn the analyzer power on.
Check the voltage between the pin 1 and pin 6(GND) of the cable within +22.0 V to +27.0
V using a voltmeter with a small probe.
If the voltmeter reading is out of the limits, replace the A40 pre-regulator.
If the voltmeter reading is within the limits, the A40 pre-regulator is veried. Turn the
analyzer power o and reconnect the cable to the A50J1. Then continue with the next
Check the A50 DC-DC Converter section.
Figure 7-6. A40J1 Output Voltage
2. Check the A50 DC-DC Converter
a.
b.
c.
d.
Turn the analyzer power o.
Disconnect a cable form the A50J3. The A50J3 location is shown in Figure 7-6.
Turn the analyzer power on.
Check the voltage between the A50J3 pin 1 and pin 6(GND) within +4.59 V to +5.61 V
using a voltmeter with a small probe.
If the voltmeter reading is out of the limits, replace the A50 DC-DC Converter.
Power Supply Troubleshooting
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