Table 5-6. Repairing the C166PSB/PSE Board Assembly (Continued)
Problem
Cause Checkpoint Solution
The 35 Vand
5 V linesare
notoutput
when the
printeris
powered on.
Q32 is dead. Check that the resistance betweenthe
collector and emitter isinfinite. Replace
the Q32.
^Q31 is dead. Check that the resistance betweenthe
source and drainis infinite. Replace
the Q31.
The +5V line
is notoutput. IC51 is dead.
Check the voltage waveform atpin 8 of
IC51. The voltagewaveform is as follows:
Check the voltage at pin 12 ofIC51.
Replace
IC51.
^
Q51 is dead. Check the voltage waveform between
emitter and collector ofQ51. Replace
Q51.
^L51 is short. Check the resistance betweenboth
terminals of L51 Replace
L51.
The PWDN
signalis
constantly
HIGH.
IC52 is dead. Check whether the voltage of pin 6 is
more than 1.3 V or not. Ifthe voltage is
more than 1.3 V, IC52 is dead.
Replace
IC52.
FX-2170 Service Manual Troubleshooting
Rev.A 5-11