Oki ML520 Service Manual page 187

4.6.03 ALARM/LED Display Troubleshooting Tables
CAUTION:
Always check that all connectors on the printer are making good contact.
Reference Failure Description
Number
1 Space Motor Alarm
2 Printhead Detection
Alarm
3 Printhead A/D Alarm
4 Printhead Gap Alarm
5 Printhead Data
Transfer Alarm
6 Printhead Type
Alarm
7 Printhead
Connection Alarm
(1)
Service Guide ML520/521
Chapter 4 Failure & Repair Analysis
Cause
Space motor IPT does
not occur in specified
time.
Printhead does not
home.
Thermistor is open or +5
vdc shorted.
Self adjustment was not
successful.
Printhead parity
error<R>was not
recovered or print head
was not seated properly.
24 pin printhead is
connected in a 9 pin
printer.
Overdrive signal is
active but no current is
detected.
Recommended Action
Refer to RAP 02.
Refer to RAP 03.
Check the printhead
connection. Then
replace the main control
board the carriage cable
and the printhead.
Check the printhead
connection. Then
replace the main control
board the carriage cable
and the printhead.
Replace the main control
board the carriage cable
and the printhead.
Replace the printhead
with a 9 pin printhead.
Check the printhead
connection. Then
replace the main control
board the carriage cable
and the printhead.
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