Epson LQ-510 - Page 183

TROUBLESHOOTING
REV.-A
Problem
Self-test
printing is
abnormal.
Symptom
Self-test
printing is
not
executed.
Table 5-7. SAMA Board Unit Repair (Cont.)
Cause
CPU cannot
measure
voltage on
the 24 V
line.
IC7A is
defective.
IC1A is
defective.
Checkpoint
Measure voltage at VAref (pin 42) of IC5B. The normal
voltage is 4.75 V.
Check output of the IC1A chip select signal at pin 58
of IC7A.
At IC1A, check HPW input signal (pin 31) and printhead
drive signal of 1A.
Solution
Replace
IC6B.
Replace
IC7A.
Replace
IC1A.
5-18
LQ-510