EPSON Stylus Photo 750 Revision A

Troubleshooting Unit Repair (Power Supply Board) 44

3.3 Unit Repair (Power Supply Board)

This section describes the problems related to the power supply board. The table below provides vari ous 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 Table 3-6. Repair of the Power Supply Board

Sympto
mCondition Cause Check point Solution
The
printer
does not
operate at
all.
+42VDC
line does
not work.
F1 is open. C heck F1 is normal or not by using
a multimeter. Replace
F1.
Trans T1 is
open. Check T1 is normal or not by using
a multimeter. Replace
T1.
FET(Q1) is
broken.
Check the drain wave.
Replace
Q1.
Q2 or Q3 is
broken.
Check the collector wave.
Replace
Q2 or
Q3.
PC1 is
broken. Replace
PC1.
Sympto
mCondition Cause Check point Solution
The
printer
does not
operate at
all.
+5VDC
line does
not work.
IC51(FA36
35A) is
broken.
Check the output wave(pin 8).
Replace
IC51.