Table 5-7. Repairing theC166 MAIN Board Assembly
Problem
Cause
Checkpoint
Solution
Paper feed is
abnormal.
IC1 is defective. IC2 is
defective. IC11 is
defective.
Check input signal waveformat pins 43
and 26 of IC11.
Check output signal waveformat pins 6,
3, 18, and 21.
If the inputsignal
is not correct,
replace IC1 or
IC2. If the input
signal is correct
and the output
signal is not
correct, replace
the IC11.
No data is
printed.
IC1 is defective. Check the output signalwaveform at pin
19 of IC1. If this signal is
not output,
replace IC1.
A particular
dotfails to
print.
IC2 is defective.
One of the head drive
transistors is defective
(Q5 ~ Q13, Q14 ~
Q22).
Check the voltage waveform (CH1) at
pin 69 andpins 76 ~ 93 of IC2.
Check the voltage waveform (CH2) for
each transistor.
If the headdrive
signal is not
output, replace
IC2. If the head
drive signal is
output, replace
the head drive
transistor.
Troubleshooting FX-2170 Service Manual
5-14 Rev. A