Epson C117001-N - DFX 5000+ B/W Dot-matrix Printer Service Manual page 151

Troubleshooting
Table 5-5. C117 PSB/PSE Board Assembly Component Repair (continued)
Symptom
The +35 The main switching
VDC line is FETs (Q101 or
dead.
QI02 or Q201 is
defective.
defective.
.
5 - 1 4
Cause
Check
the drain side and GND.
r I
Observe the voltage waveform
between the collector side and GND.
I I
1
Check the voltage waveform between
the collector side and GND.
I
Checkpoint
voltage waveform between
I 1 I I
1
1
I I I . + I
A
I
I
I
Solution
Replace
I
Replace
2203.
Rev. A