Epson 440 - Manual (Page 89)

EPSON Stylus Color 440/640/740 Revision A
Chapter 3 Troubleshooting 89
Table 3-5. Repair of the C206/C257 PSB/PSE Board
Symptom Condition Cause Checkpoint Solution
The printer does
not operate at all. +42V line is dead. F1 is open. Check F1 by using a
tester. Replace F1.
Transformer coils are open. Check the waveform at the drain of Q1. Replace T1.
Switching FET (Q1) is
dead. Check drain side. Replace Q1.
Feed back transistor (Q2,
Q3) are dead. Check collector side. Replace Q2 or Q3.
+42 V line is abnormal. Check the following parts.
• ZD87, ZD83
• ZD51, ZD81–ZD86
• PC1
Replace suitable
parts.