Unit Repair - C164 Main Board - Epson STYLUS PRO XL 4004677 Service Manual

Troubleshooting
5.4 UNIT REPAIR - C162 MAIN BOARD
This section describes the problems related to the main controller board (C162 MAIN). The table
below provides various symptoms, likely causes, and checkpoints.
waveforms, resistance, and other values to be checked to evaluate the operation of each component
Symptom Condition
The CPU
does not
operate.
The (Drive
printer system does
does not not operate
operate at normally
all. when you
turn the
printer on or
off.)
The
The carriage
carriage
motor does
does not
not operate
operate
at all.
normally.
5-10
Table 5-6. Repair of the C162 MAIN
Cause
Check the waveform of the +5 V
line and that of the RESET signal.
The reset circuit
does not operate.
Check pin 2 of IC3 for a change
in the signal HIGH/LOW.
Selection of
control ROM is
abnormal.
Either CG or
RAM is defective.
Check the oscillator signal at
either pin 75 or 74 of the CPU.
CPU is defective.
Check the serial signal output
from pin 25 or 27 of IC2 to
the driver IC15.
IC2 is defective.
CPU is defective.
The checkpoints refer to
Checkpoint
Stylus Pro XL
Solution
Replace IC13
or IC8.
Replace IC1.
Replace CG
or RAM.
If signal is
detected,
replace CPU.
Otherwise
replace CR1.
Replace IC2.
Replace CPU.
Rev. -A