Troubleshooting For Electrical Circuit; Power Supply Board (B054Psh Board) - Epson GT-1200 Service Manual

GT-12000

3.1.3 Troubleshooting for Electrical Circuit

This section describes the abnormal phenomenon and corresponding
check points for each electrical circuit board.

3.1.3.1 Power Supply Board (B054PSH Board)

Phenomenon
<Abnormal voltage>
+5VDC is not output.
<Abnormal voltage>
+24 VDC is not output.
<Abnormal voltage>
+15 VDC in not output.
Rev. A
Check Points
Check IC51 (TL494):
· Signal waveform output from
Pin 8/11 (chopping waveform)
Check the Switching FET/Q1:
· Waveform at the drain
Check IC52 (78M15):
· Signal waveform output from
Pin 1
Troubleshooting
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