JCM GOLD GP-965 Service Manual - page 12
GP-965 service
manual
12
Abnormal
driver/receiver in serial
port
Faulty U4
Check the signals at
pin7~14 of U4
Replace U4
The wrong
characters
are printed
Abnormal
driver/receiver in
parallel port
Faulty U5
Check the signals at pin1~9
of U5
Replace U5
4.2 Panel SW Circuit Board Unit
PHENOMENON
DETAIL
CAUSE
CHECK
REPAIR METHOD
Faulty switches
Check the switch
Replace the switches
The panel switches don’t
operate properly
Broken cable
Check the cable
Replace the cable
Faulty switches
Check the switch
Replace the switches
Abnormal release
operation
No paper release
is performed
Broken cable
Check the cable
Replace the cable
Faulty switches
Check the switch
Replace the switches
Paper reverse is
abnormal
No paper reverse
isn’t performed
Broken cable
Check the cable
Replace the cable
Power LED doesn’t
light
Printing is normal Faulty LED
Check the LED
Replace the LED
4.3 Power Supply Circuit Board Unit
PHENOMENON
DETAIL
CAUSE
CHECK
REPAIR METHOD
CN101 (AC input)
and CN102 (DC
output) aren’t
connect good
Check CN101 and
CN102
Connect CN101 and
CN102 well
F101 (FUSE) is
broken, and/or
faulty RT101
Check the FUSE and
RT101
Replace the FUSE and/or
RT101
Faulty diodes
D101, D102 and
D103
Check diodes D101,
D102 and D103
Replace diodes D101,
D102 and/or D103
Faulty U101
Check U101
Replace U101
Faulty U102
Check U102
Replace U102
Power LED doesn’t
light
Printer doesn’t
operate
Faulty Q101
(TOP224)
Check Q101
Replace Q101