Epson DFX-8500 Service Manual page 195

Table 5-6. C204 MAIN/DRV/DRV-B boards Component Repair 6/7
Symptom
The head fan IC1 on the C204
operation is MAIN board is
abnormal. defective.
Q10 or Q11 on the
C204 MAIN board is
defective.
The PG motor IC1 on the C204
operates MAIN board is
abnormally. defective.
The common
switching transistor on
the C204 DRV board
is defective.
The phase switching
transistor on the C204
DRV board is
defective.
Fuse F2 on the C204
DRV board is
defective.
The PG sensor is
defective.
The PG home
position sensor is
defective.
The plunger is Fuse F3 is defective
defective.
IC1 on the C204
MAIN board is
defective.
Plunger drive
transistor on the C204
DRV board is
defective.
Rev. B
Cause
Observe the PG motor phase signal at
pins 163 (FANA) and 164 (FANAX) of
IC1.
Observe the head fan phase drive
voltage level for pins 25 (HFANA) and
17 (HFANB) of CN1. (The normal
voltage is approximately 37 VDC.)
Observe the PG motor phase signal at
pins 10 (PGA), 12 (PGB), 14 (PGAX),
and 13 (PGBX) of IC1.
Check the collector voltage of Q11.
For transistors Q12 - Q15, observe the
output signal (collector).
Check if fuse F2 is defective.
Observe the PG sensor output signal at
pins 35 (PGENCA) and 34 (PGENCB)
of CN14.
Observe the PG HP sensor signal level
for pin 36 (PGHOME) of CN14.
(PG home = LOW level; other = HIGH
level.)
Check if fuse F3 is defective.
When paper is loaded into the printer,
look at the switching signal at pins 16
(PLP) and 17 (PLN)of IC1.
Observe the Q31 collector voltage at
paper loading.
Checkpoint
TROUBLESHOOTING
Solution
Replace IC1.
Replace Q10 or
Q11.
Replace IC1.
Replace Q10 or
Q11.
if there is no output
signal, replace the
abnormal transistor.
Replace F2.
Replace the PG
sensor.
Replace the PG
home position
sensor.
Replace F3.
Replace IC1.
Replace Q31, Q30,
or Q32.
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