Epson FX-870 Service Manual page 148

Table 6-7. Repairing the C076 PSB Board Assembly (Continued)
Problem
The +35 V line is
he +5 V line is
bad.
ad.
bad.
Epson FX-870/1170
Checkpoint
Check the +35 V line.
Check the oscillation waveform (IC51 pin 5) and the
switching waveform (IC51 pin 8).
Check the switching waveform at Q52 emitter.
Principles of Operation
Solution
Refer to the
items
described
above.
Replace
Replace
Q52.
6-33