REV.-A
5.4 Repairing the Board Assembly,
MAIN
This section provides instructions for repairing the BOARD ASSEMBLY,
MAIN. It describes various
problems, symptoms, likely causes, checkpoints, and solutions. The checkpoint column provides proper
waveforms, resistance values, and other information for each component of the
MAIN.
Table 5-5. Repairing the BOARD ASSEMBLY,
MAIN
Problem
Symptom
Cause
Checkpoint
Solution
Abnormal
The CPU
The reset
Check the voltage waveforms of the VDD (+5
Replace
at
does not
circuit is
pin 41) and ROUT
pin 15) when the
power on.
operate
defective.
power is turned on.
properly.
-1-
1
I I I I
I
I
1 I
1 I
I
I 1
I I
+
IS
[
1
1
The control
Check the signal HIGH/LOW alternation
Replace
ROM is not
pin 4).
selected.
1
Either the
Replace IC2
ROM
or the
or
IC3.
RAM
is
defective.
5-14
Summary of Contents for FX 1170 - B/W Dot-matrix Printer
Page 1: ...EPSON EPSON TERMINAL PRINTER FX 870 1170 SERVICE MANUAL 4001461 REV A ...
Page 5: ... f REVISION SHEET REVISON DATE ISSUED CHANGE DOCUMENT A June 15 1992 1st issue 7 v ...
Page 11: ...REV A 4 80 column model 136 column model Figure 1 1 External View of the FX 870 1170 r 1 2 ...
Page 128: ...REV A Figure 6 1 Lubrication Points 6 3 ...
Page 135: ......
Page 136: ......
Page 137: ......
Page 138: ...EPSON ...