Lexmark T520 - 20ppm 8MB Par USB Pcl6 Ps3 Ppds Service Manual page 108

4520-xxx
FRU
1 Operator Panel Cable
2 Operator Panel Display
blank, 5 beeps, LED Off
3 Operator Panel Display
blank, 5 beeps, LED On
4 Operator Panel all
diamonds, No Beeps
5 Operator Panel all
diamonds, 5 Beeps
2-80
Service Manual
Action
Check for proper installation of the
cable at the engine board (J11) and
at the operator panel. Check the
continuity of the operator panel
cable. If incorrect, replace the cable.
Check the voltage at J11-2 on the
engine board. It measures
approximately +5 V dc. If incorrect,
replace the engine board. If correct,
replace the operator panel assembly.
Check for ground between J13-4 and
ground. If correct, replace the
operator panel assembly. If incorrect,
replace the engine board.
Check to make sure a card is not
plugged in backward. This condition
causes the printer to fail POST
displaying all diamonds on the
operator panel with no beeps.
Check the voltage at Pin J11-1 and
J11-3. The voltage measures
approximately +5 V dc. If incorrect,
replace the FRUs in the following
order:
1. Operator panel assembly
2. Engine board