Operator Panel Display Blank, Five Beeps - Lexmark C540n Service Manual

5025-2xx, 4xx

Operator panel display blank, five beeps

Service tip: The printer has detected a problem with the controller board, the operator panel assembly cable
(part of the front cover assembly), or the operator panel assembly if POST does not complete. The printer emits
five beeps, and sticks in a continuous pattern until the printer is turned off.
Step Questions / actions
1 Is the operator panel assembly cable properly
installed at controller board JOPP1 and at the
operator panel assembly?
2 Turn the printer off, and remove the rear
shield. See "Top cover assembly removal"
on page 4-13.
Turn the printer on, and verify the following
values at JOPP1:
Pin
Are the values approximately correct?
3 Check continuity of the operator panel
assembly cable.
Is there continuity?
2-34
Service Manual
JOPP1
Value
2 +5 V dc
4 Ground
5 +5 V dc
6 +3.3 V dc
7 Ground
Yes
Go to step 2.
Go to step 3.
Replace the operator panel
assembly. See "Operator
panel logo plate" on
page 4-9.
No
Reinstall the cable.
Replace the controller
board. See "Controller
board removal" on
page 4-20.
Replace the front cover
assembly. See "Front
cover assembly removal"
on page 4-2.