Epson DFX 8500 Service Manual page 183

Table 5-5. C204
I 'SI
v
37 VDC
line
(VP3)
3lPSE Board Component Repair 3/3
Checkpoint
Check the voltage level at pin 10 (Vl)
and pin5 (GP).
Solution
Replace IC204.
Observe the drive waveform at pin 6 Replace IC204 or
(VO) and pin 5 (GP).
zD211.
When the input voltage of the minus
Replace IC203.
port (pin 6 for VP1 and pin2 for VP2) is
less than u VDC, the comparator
outputs a HIGH signal.
When the input voltage of the plus port Replace IC203.
is bigger than u VDC, the comparator
outputs a HIGH signal.