Epson Stylus COLOR 440 Service Manual page 87

EPSON Stylus COLOR 440, 640, and 740
Symptoms Condition
The printer does not CPU does not operate.
operate at all.
(Continued on the next
(Continued on the next
page.)
page.)
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 of
IC9.
Pin 7 = +5 volts
Pin 6 = /Reset
Stylus COLOR 740:
Check the waveform of the
+5V and /Reset signal at
IC8.
Pin 7 = +5 volts
Pin 2 = /Reset
Control ROM, D-RAM, Stylus COLOR 440:
and Mask ROM are
If you cannot find a waveform at the following pins, their
defective, or are not respective ICs are defective:
being selected
Pin 88 of IC1
correctly. Pin 20 of IC3
Pin 26 of IC4
Stylus COLOR 640:
If you cannot find a waveform at the following pins, their
respective ICs are defective:
Pin 97 of IC1
Pin 13 of IC3
Pins 98 and 99 of IC1
(Continued on the next
Pin 27 of IC5
page.)
Pin 14 of IC6
Chapter 3 Troubleshooting
Solution
Replace IC9.
Replace IC8.
Stylus COLOR 440:
Replace IC1, IC3, or IC4.
Stylus COLOR 640:
Replace IC1, IC3, IC5, or IC6
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