Lexmark C 540n, Service Manual

Page: 67 / 262

Diagnostic information
2-33
5025-2xx, 4xx
Operator panel service check
Warning: Replace one of the following components, and perform a POR before replacing a second
component. Never replace both of the components without performing a POR after installing each
one, or the printer will be rendered inoperable:
•
Operator panel assembly
•
Controller board
Warning: Never install and remove components listed above as a method of troubleshooting components.
Once a component has been installed in a printer, and the printer is powered on, it cannot be
used in another printer. It must be returned to the manufacturer.
One or more operator panel buttons fail
Step Questions / actions Yes No
1 Enter Diagnostics Menu (turn the printer off,
press and hold
and , turn the printer on,
and then release the buttons when the
installed memory and processor speed
displays).
Perform the Panel Test. See “Panel Test” on
page 3-11 . The Panel Test should show
alternating display of all pixels on, and all
pixels off. Press
Stop to end the test.
Did the test show errors on the display?
Replace the operator panel
assembly. See
“Operator
panel logo plate” on
page 4-9
.
Go to step 2.
2 Perform the Button Test. See “Button Test”
on page 3-12 in Diagnostics Menu.
Did any of the buttons fail the test?
Replace the operator panel
assembly. See
“Operator
panel logo plate” on
page 4-9
.
Go to step 3.
3 Remove the rear shield. “Top cover
assembly removal” on page 4-13 .
Turn the printer on, and verify the following
values at JOPP1:
Are the values approximately correct?
Replace the operator panel.
See
“Operator panel logo
plate” on page 4-9 .
If this does not fix the
problem, replace the front
cover assembly which
contains the operator panel
cables. See
“Front cover
assembly removal” on
page 4-2
.
Replace the controller
board. See
“Controller
board removal” on
page 4-20
.
JOPP1
Pin Value
2 +5 V dc
4 Ground
5 +5 V dc
6 +3.3 V dc
7 Ground