Epson FX 890 - B/W Dot-matrix Printer User Manual

FX-1180/FX-880 Service Manual
Chapter 3 Troubleshooting
Rev. B
3-11
3.3 UNIT REPAIRING OF THE POWER SUPPLY BOARD
This section is necessary only for servicers who repair to the component level. Servicers who
perform only board replacement can ignore this section.
The table below lets you troubleshoot problems with the power supply board
(C229PSB/PSE/PSH). The table provides various symptoms, likely cases, and checkpoints.
Checkpoints include waveforms, resistance, and other values to be checked to evaluate the
operation of each component.
Table 3-7. Repair of the C229PSB/PSE/PSH
Symptom Condition Cause Checkpoint Solution
The printer
dose not
operate at
all.
+35V line is
defective.
Fuse F1 is
blown.
Check that the fuse is not blown. Replace the
C229PSB/
PSE/PSH
board.
Transformer
(T1) is open.
Check the coil of transformer using
a multimeter.
Replace the
C229PSB/
PSE/PSH
board.
Switching
FET (Q1) is
defective.
Check for the proper waveform at
the drain of Q1.
Figure 3-10. Drain of Q1
Replace the
C229PSB/
PSE/PSH
board.
Q2 or Q3 is
defective.
Check for the proper waveform at
the collector of Q2 or Q3.
Figure 3-11. Collector of Q2/Q3
Replace the
C229PSB/
PSE/PSH
board.

Epson FX 890 - B/W Dot-matrix Printer Specifications

General

Brand	Epson
Model	FX 890 - B/W Dot-matrix Printer
Category	Printer
Language	English