Service manual

QMS 3260/4032 Laser Printer - Base Engine Technical Manual 4-7
Release Version 11-97
Primary Fault Isolation Procedures
4.3 Inoperative Control Panel
The Control Panel LEDs, LCD, and/or Keypad do not function or do not function correctly.
Step Actions and Questions Yes No
SUSPECT COMPONENTS
The followin
g
components are associated with this specific
problem. One or more of these components ma
y
have failed
partiall
y
or completel
y
. If
y
ou cannot isolate the problem usin
g
this FIP, replace each component listed below, one at a time,
until the problem disappears.
• wiring and connectors linking the components
• QMS Video Controller (RRP 9.7)
1
CONTROL PANEL TEST
1. Remove the Control Panel from the Top Cover
(
RRP 1.5
)
2. Connect the Control Panel to P 410 on the MCU PWB.
3. Enter Dia
g
nostic Mode
(
See Section 7
)
.
When you enter Diagnostic Mode do the Control Panel
LEDs light up and does the LCD display Chn-00 Fun-00?
Go to step 2 Go to step 3
2
ESS MOTHER PWB REPLACEMENT
Replace the ESS Mother PWB (RRP 9.10).
Is the
p
roblem still
p
resent?
Replace the
MCU PWB
(
RRP 9.7
)
Problem
solved
3
LVPS +5VDC CHECK
Measure the voltage between J400-7 and FG, and between
J400-8 and FG on the MCU PWB.
Is there +5VDC between J400-7 and FG, and is there
+5VDC between J400-8 and FG.
Replace the
Control Panel
(
RRP 1.5
)
Replace the
LVPS Assem-
bl
y
(
RRP 9.2
)