Epson Stylus Color 640 Service Manual page 92

EPSON Stylus Color 440/640/740
Symptoms Condition
The printer does not CPU does not operate.
operate at all.
(Continues to the next
(Continues to the next
page.)
page.)
Chapter 3 Troubleshooting
Table 3-6. Unit Repair of Main Board
Cause Check Point
The reset circuit does not Stylus Color 440, 640:
operate.
Check the waveform of the
+5V and /Reset signal
(IC9=Pin 7, 6-pin)
Stylus Color 740:
Check the waveform of the
+5V and /Reset signal
(IC8=2-pin, Pin 7)
Control ROM, D- RAM,
Stylus Color 440:
and Mask ROM are not
If you can not find the waveform at 88-pin of IC1, the IC1 is
selected correctly or it's
dead, and if you can not find it at 20-pin of IC3 or 26-pin of
dead.
IC4, the IC3 or IC4 is dead.
Stylus Color 640:
If you can not find the waveform at 97-pin of IC1, the IC1 is
dead, and if you can not find it at 13-pin of IC3, the IC3 is
dead. If you can not find the waveform at 98, 99-pin of IC1,
(Continues to the next
the IC1 is dead, and if you can not find it at 27-pin of IC5, and
page.)
at 14-pin of IC6, the IC5 or IC6 is dead.
Revision A
Solution
Replace IC9.
Replace IC8.
Stylus Color 440:
Replace IC1, IC3, or IC4.
Stylus Color 640:
Replace IC1, IC3, IC5, or IC6
92