Repairing C244 Main Board Assembly - Epson fx-2180 Service Manual

FX-2180 Service Manual

3.5 REPAIRING C244 MAIN BOARD ASSEMBLY

This section provides instructions for repairing C244 MAIN board
assembly. It describes various problem, symptoms, likely cases and
solutions. The check points columns provide proper waveforms, resistance
values and other information for each component of C244 MAIN.
CAUTION
This information is necessary only for servicers
who repair to the component level. Servicers who
repair to the unit level (including all servicers in
the U.S.) can ignore this section.
Table 3-10. Repairing C244 MAIN Board Assembly
Problem Cause
The Reset Check the voltage waveforms
printer IC15 is of the VCC signal (CH1 : IC15
dose not defective. pin 7) and /RESET signal (CH2
operate : IC15 pin 5) when the printer is
at all. turned on.
Figure 3-12. Waveform 5
Rev. A
Checkpoint Solution
Replace the
main board or
IC15.
CH 1
CH 2
Table 3-11. Repairing C244 MAIN Board Assembly (Continued.)
Problem Cause
The The Check the signal for a change
printer PROM in HIGH and LOW at pin 137
dose not (IC5) is of IC1.
operate not
at all. selected.
Figure 3-13. Waveform 6
The Check the signal for a change
PSRAM in HIGH and LOW at pin 132
(IC3) is of IC1.
not
selected.
CPU (IC2) Check the oscillator signal at
is pins 26 or 27 of the CPU
defective.
Figure 3-14. Waveform 6
Troubleshooting
Checkpoint Solution
Replace the
main board.
Replace the
main board.
Replace the
main board.
3-9