Control Panel Operation Is Abnormal; Unit Repair (Power Supply Board) - Epson Stylus COLOR 670 Service Manual

EPSON Stylus COLOR 670

3.2.5 Control panel operation is abnormal

START
Control
panel connected
correctly?
YES
Replace the
control panel.
Control
panel connected
correctly?
YES
END
Flowchart 3-5.
Troubleshooting
NO
Connect the
control panel
correctly.
Is the
YES
problem
solved?
NO
NO
Replace the
MAIN Board.
END

Unit Repair (Power Supply Board)

3.3 Unit Repair (Power Supply Board)
This section provides in-depth information for repairing the power supply
board so that you can repair the board to the small parts level. The table
below lists the probable causes for each symptom: you can select appropriate
symptom from the table and check each parts and its function as described in
the checkpoint.
Table 3-5. PSB Troubleshooting
Symptom Condition Cause
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.
Revision A
Check point Solution
Check F1 is normal or not by Replace
using a multimeter. F1.
Check T1 is normal or not by Replace
using a multimeter. T1.
Check the drain waveform.
Replace
Q1.
Check the collector wave.
Replace
Q2 or Q3.
Replace
PC1.
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