Xerox DocuPrint C55 Service Manual page 47

OF2.3 The message display is flickering
off and on, or displaying random
characters.
PROCEDURE
Refer to BSD 2.1 and check the following
signals:
• If the Message is flickering off and on,
check CN103-27 (DATA 1) for an open.
• If the Message is illegible, and the K LED is
on all the time, check CN103-25 (DATA 3)
for a short to ground.
• If the Message is illegible, and the M LED
is on all the time, check CN103-27
(DATA 1) for a short to ground.
• If the Message is illegible, and the Y LED is
on all the time, check CN103-28 (DATA 0)
for a short to ground.
If all appear OK, replace the Control Panel
PWB,
If the problem still exists, replace the PCU
PWB.
DocuPrint C55/C55mp/[NC60]
OF2.4 Message display works OK, LEDs
do not work correctly.
PROCEDURE
If the On Line LED never comes on, refer to
BSD 6 and check the following:
• CN104-6 CRDY (Command Ready) for an
open.
• CN104-2 CMD (Command) for an open or
a short.
If the LEDs are flickering off and on, refer to
BSD 2.1 and check the following:
• CN103-21 LED Enable for a short to
ground.
If the LEDs are off, refer to BSD 2.1 and check
the following:
• CN103-21 LED Enable for an open.
If all appear OK, replace the Control Panel
PWB.
If the problem still exists, replace the PCU
PWB.
2/99
2-33
OF2.5 Message display works
Switches do not work correctly.
PROCEDURE
When the switches do not work properly, refer
to BSD 2.1 and check the following:
• CN103-20 Switch Enable for an open or a
short.
If OK, replace the Control Panel PWB.
If the problem still exists, replace the PCU
PWB.
OTHER FAULTS RAPs
OK,
OF2