Epson DLQ-3000+, Service Manual

Page: 155 / 262

DLQ-3000+
Rev. A
5-16
Table 5-13. Repair of C210 MAIN Board (continued)
Condition Cause Check point Solution
Symptom : Abnormal printing
Printhead
control circuit
operates
abnormally. Printhead control
circuit is
defective.
If some particular dots are missing or
bad, check which head driver is
causing the problem, the driver for
print pulse A or B.
If any of the drivers is bad, see the
circuit diagram and replace the
corresponding drive transistors (
to ,
$
to
$
). (See Note 1.)
If both drivers are good, gate array
is defective.
Figure 5-14. Head Drive Signal Waveform
Replace the
main control
board or
associated
component.
Printhead driver
circuit is
defective.
Check pin 3 of 3-terminal regulator
!
for the correct output voltage
%
&
If it’s correct, gate array is
defective.
Replace the
main control
board or any
associated part.
PG motor is not
functioning
properly. PG motor driver
circuit is
defective.
Check pins 1,3,5,and 7 of
$
for the
input signal waveform and pins 15/16,
13/14, 11/12 and 9/10 of
$
for
output signal waveform.
If no motor phase input signals is
input, gate array is defective.
If no drive waveforms is output,
$
is defective.
Figure 5-15. PG Motor Drive waveform
Replace the
main control
board or any
associated
parts.
Note:
1.
-No. shown in the diagram and corresponding dot No. are the same.