Repairing The C165 Main Board Assembly - Epson LQ-2170 Service Manual

Troubleshooting

5.5 REPAIRING THE C165 MAIN BOARD ASSEMBLY

This section provides instructions to repair the C165 MAIN board assembly. It describes various problems,
symptoms, likely causes, and solutions. The checkpoint column provides proper waveforms, resistance
values, and other information for each component of C165 MAIN.
Note:
This information is necessary only for servicers who repair to the component level. Servicers who
repair to the unit level (including all servicers in the U.S.) can ignore this section.
Table 5-7. Repairing the C165 MAIN Board Assembly
Problem
The printer
does not
Reset IC10 is defective.
operate at all.
The PROM (IC3) is not
selected.
^
The PSRAM (IC5)
^
5-12
Cause
Check the voltage waveforms of the VCC
signal (CH1: IC10 pin 3 ) and VOUT signal
(CH2: IC10 pin 1) when power is turned
on.
Check for a change in the signal from
HIGH/LOW at pin 137 of IC2.
Check for a change in the signal from
HIGH/LOW at pin 132 of the IC.
LQ-2170 Service Manual
Checkpoint Solution
Replace IC10.
Replace IC2 (or
replace the main
board).
Replace IC2 (or
replace the main
board).
Rev. A