Unit Repair - C172 Psb/Pse Board - Epson Stylus 1500 Service Manual

Troubleshooting
5.3 UNIT REPAIR — C172 PSB/PSE BOARD
This section is necessary only for servicers who repair to the component level. Servicers who perform only
board replacement (including all U.S. servicers) can ignore this section.
The table below lets you troubleshoot problems with the power supply board (C172 PSB/PSE). The table
provides various symptoms, likely causes, and checkpoints. Checkpoints include waveforms, resistances, and
other values to be checked to evaluate the operation of each component.
Symptom
Condition
+42 V line
is dead
The printer
does not
operate at all
+5 V line is
de ad .
5-10
Table 5-5. Repair of the C172 PSB/PSE
Cause
Check whether F1 is normal
F1 is open.
or not.
Check the coils for transformer
Transformer
using a multimeter.
(T1) is open.
Check the waveform at drain of Q1
Switching
FET(Q1)
is dead.
Check the waveform at corrector
of Q2 or Q3.
Q2 or Q3
is dead.
Check the pin 5 or 7 waveform of PC1.
PC1 is
d e ad .
Check the pin 5 waveform of L4962.
Regulator
IC L4962
is dead.
Check the pin 7 waveform of L4962.
Stylus 1500 Service Manual
Checkpoint
Solution
Replace F1.
Replace T1.
Repla ce Q1 .
Replace Q2 or
Q 3 .
Repla ce PC1.
Replace L4962.
Replace L4962.
Rev.A