Unit Repair (Power Supply Board) - Epson Stylus Photo 750 Service Manual

EPSON Stylus Photo 750

3.3 Unit Repair (Power Supply Board)

This section describes the problems related to the power supply board. The table below provides various symptoms, likely causes, and checkpoints.
The checkpoints refer to waveforms, resistance, and other values to check to evaluate the operation of each component.
Table 3-5. Repair of the Power Supply Board
Sympto
Condition Cause
m
F1 is open.
Trans T1 is
open.
FET(Q1) is
broken.
The
printer +42VDC
does not line does
operate at not work.
all.
Q2 or Q3 is
broken.
PC1 is
broken.
Troubleshooting
Check point
Check F1 is normal or not by using
a multimeter.
Check T1 is normal or not by using
a multimeter.
Check the drain wave.
Check the collector wave.
Unit Repair (Power Supply Board)
Table 3-6. Repair of the Power Supply Board
Sympto
Solution Condition
m
Replace
F1.
Replace
T1.
The
printer
+5VDC
does not
line does
operate at
not work.
all.
Replace
Q1.
Replace
Q2 or
Q3.
Replace
PC1.
Cause Check point
Check the output wave(pin 8).
IC51(FA36
35A) is
broken.
Revision A
Solution
Replace
IC51.
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