Epson DFX-8500 Service Manual page 194

DFX-8500
Table 5-6. C204 MAIN/DRV/DRV-B boards Component Repair 5/7
Symptom
Paper feeding is The CPU IC2) on the
abnormal. C204 MAIN board is
defective.
IC2 on the C204 DRV
board is defective.
Ribbon feeding is The CPU IC2) on the
abnormal. C204 MAIN board is
defective.
The common
switching transistor on
the C204 DRV board
is defective.
The phase switching
transistor on the C204
DRV board is
defective.
Fuse F1 on the C204
DRV board is
defective.
5-20
Cause
Check the PF motor phase drive
signals at pins 2 - 5 of IC2.
At IC2, check the output signals for
pins 2 (OUT_A), 3 (OUTXA), 6
(OUT_B), and 7 (OUTXB).
Check the RF motor phase drive
signals at pins 6 - 9 of IC2.
Check the collector voltage of Q21.
For transistors Q22 - Q25, observe the
input signal from the CPU (base) and
the output signal (collector).
Check if fuse F1 is defective.
Checkpoint Solution
Replace IC2.
Replace IC2.
Replace IC2.
Replace Q20 or
Q21.
if there is no output
signal, replace the
abnormal transistor.
Replace F1.
Rev. B