Service manual

EPSON Stylus Color 300 Service Manual
Rev. A
5-2
Symptom Condition Cause Checkpoint Solution
Self-test
printing is
abnormal.
No printing. PWM signal is
not output.
Is PWM signal waveform correct at pin
140 of IC1?
Replace IC1
Head drive
voltage
generation
circuit does
not operate.
Check waveform of the signal VO: Replace any
defective
components:
Q1/2/4/7/8 or
QM1/3/4/5/6/7/8
Carriage
does not
operate
normally.
Drive signals
are not
output
correctly.
CPU (IC2) is
defective
Is the signal waveform correct at pin 5/6
of IC2?
Replace IC2
CR Motor
driver (IC8) is
defective
Is the signal waveform correct at pin
3/6/18/21 of IC8?
Correct:
Replace CR
Motor
Incorrect:
Replace IC9