Lexmark 4227 - Forms Printer B/W Dot-matrix Service Manual page 53

4227-300
FRU/Symptom
2 63E Head
Thermal Error
3 Auto Gap
4 Printhead Cables
5 Sub Logic Board
6 Ribbon
7 Printhead
Action
The printer has stopped to protect the
printhead from overheating. Normally this
occurs after several hours of continuous heavy
use in a warm environment, and only then after
going through several stages of thermal
slowdown.
Wait for the machine to cool and see if the
error goes away.
If the machine was not being used heavily
before the error occurred, or if the error returns
when the machine is cool, replace the
printhead.
If the printhead is firing, manually rotate the
carrier shaft during printing by pushing down
on the Auto Gap Home sensor flag.
If printing starts and is correct, go to the
Gap service check" on page 2-11
Inspect for improper connection or damage.
If there is carrier motion but no printhead noise,
and the printhead cables do not appear to be
the problem, replace the sub logic board.
A problem with the ribbon shield can keep the
print wires too far from the page.
Inspect the ribbon shield. When the printer is
Ready with the ribbon installed, make sure the
ribbon shield can float slightly front to back.
The printhead probably is not the problem if
there is no printing.
Check the winding resistances as described
above and look for open circuits or shorts
between neighboring pins.
Do not replace the printhead unless a specific
problem is found.
Diagnostic information
"Auto
.
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