5.5 REPAIRING THE C166 MAIN BOARD ASSEMBLY
Thissection provide sinstructions torepair the C166 MAINboard assembly. It describes various problems,
symptoms, likelycauses, and solutions. Thecheckpoint column provides proper waveforms,resistance
values,and other informationfor each component ofC166 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.) canignore this section.
Table 5-7. Repairing theC166 MAIN Board Assembly
Problem
Cause Checkpoint Solution
The printer
does not
operate at all. Reset IC10 is defective.
Check the voltage waveforms of the VCC
signal (CH1: IC10 pin 3 ) and VOUTsignal
(CH2: IC10 pin1) when power isturned
on.
Replace IC10.
^
The PROM (IC3) is not
selected. Check for a change in the signalfrom
HIGH/LOW at pin 137of IC2. Replace IC2 (or
replace the main
board).
The PSRAM (IC5) Check for a change in the signalfrom
HIGH/LOW at pin 132of the IC. ReplaceIC2 (or
replace the main
board).
Troubleshooting FX-2170 Service Manual
5-12 Rev. A