Table 5-7. Repairing the C186 MAIN Board Assembly
Problem
Cause
Checkpoint
Solution
The printer
does not
operate at all.
CRU1 is defective.
Check the oscillator signal at pins 26
or 27 of the CPU
If the signal is not
correct, replace
IC1 ( or replace
the main board).
Otherwise,
replace CRU1.
Carriage
operation is
abnormal.
IC12 or IC1 is defective.
Check input signal waveform (CH1)
at pins 6, 5, 17, and 16 of IC1.
Check output signal waveform (CH2)
at pins 8, 1, 18, and 11 of IC12.
If the input signal
is not correct,
replace IC1 (or
replace the main
board). If the
output signal is
not correct,
replace IC12.
IC1 is defective.
Check the output signal at pins 32,33,
34, 35 of IC1
If there is no
output signal,
replace IC1 (or
replace the main
board.)
Troubleshooting
LQ-2070 Service Manual
5-14
Rev. A
Summary of Contents for 2070 - LQ B/W Dot-matrix Printer
Page 1: ...EPSON TERMINAL PRINTER LQ 2070 SERVICE MANUAL EPSON 4006244 ...
Page 5: ...REVISION SHEET Revision Issued Date Revision Page Rev A April 8 1996 1st issued ...
Page 11: ...Product Description LQ 2070 Service Manual Figure 1 1 Exterior View of the LQ 2070 1 2 Rev A ...
Page 55: ...LQ 2070 Service Manual Operating Principles Rev A 2 7 ...
Page 58: ...Operation Principles LQ 2070 Servcie Manual 2 10 Rev A ...
Page 63: ...Down LQ 2070 Service Manual Operating Principles Rev A 2 15 ...
Page 112: ...Disassembly and Assembly LQ 2070 Service Manual 3 34 Rev A ...
Page 146: ...Maintenance LQ 2070 Service Manual 6 4 Rev A ...
Page 165: ...EPSON ...