Lexmark W820 Service Manual page 115

Error Code 912
There is a problem with the Printhead.
Logic Control on the MCU PWB detected that the Printhead Motor has not come up to full
speed within the specified time.
Step Actions and Questions
1 RESET
1. Switch off printer main power.
2. Wait one minute.
3. Switch on printer main power.
Does the 912 error code appear?
2 PRINTHEAD MOTOR TEST
Enter Diagnostic Mode to run a Print Test.
Does the Printhead Motor Start?
3 +24VDC CHECK
Measure the voltage between J400-8 and FG on the MCU
PWB.
Is there +24VDC between J400-8 and FG?
4 MCU PWB REPLACEMENT
Replace the "Engine Board (MCU PWB)" on page 4-92
Does the error code appear?
5 The following printer FRUs and areas are associated with this
specific problem. One or more of these FRUs or areas may
have failed partially or completely. If you cannot isolate this
problem using the steps in this Service Check, replace each
FRU or troubleshoot each area listed below, one at a time, until
you isolate and solve the problem.
•
Wiring and connectors linking the FRUs
•
I/O PWB - Go to
4025-XXX
"I/O PWB" on page 4-89.
Yes No
Go to step 2 Suspect an
intermittent
problem with
the MCU
PWB, the
Printhead
Motor, the
SOS Sensor,
or the
connectors
and wiring
linking these
FRUs.
Go to step 4 Go to step 3
Replace the Use the Block
"Printhead Diagrams in
Assembly" the printer
on page 4-57 service
manual to
troubleshoot a
loss of
+24VDC
Go to step 5 Problem
solved
Diagnostic Information
2-19