Service manual

3-
10 QMS 3260/4032 Laser Printer - Base Engine Technical Manual
Release Version 11-97
Primary FIPS: Error Codes
3.7 Error Code U4-1
There is a problem with the Fuser.
Logic Control on the MCU PWB detected that the Thermistor remained on for longer than the specified
time.
Step Actions and Questions Yes No
SUSPECT COMPONENTS
The following components are associated with this specific
problem. One or more of these components may have failed
partially or completely. If you cannot isolate the problem using
this FIP, replace each component listed below, one at a time,
until the problem disappears.
•
wiring and connectors linking the components
1
FUSER WARM-UP
1. Switch off printer main power.
2. Remove the Fuser Full Cover (RRP 1.1) so you can
observe the Heat Rods.
3. Switch on printer main power and observe the ends of the
Fuser Assembly.
Do the Heat Rods glow?
Go to step 4 Go to step 2
2
FUSER AC POWER
1. Switch on printer main power.
2. Measure the AC voltage between J23-2 and J23-6 on the
AC Driver PWB.
Is there 110VAC between
J23-2 and J23-6
?
Go to step 3 Replace the
AC Driver
PWB (RRP
9.3)
3
Replace the MCU PWB (RRP 9.7)
Does the U4-1 error code appear?
Go to step 4 Problem
solved
4
Replace the Fuser Assembly (RRP 6.1)
Does the U4-1 error code appear?
Refer to the
wiring dia-
grams Section
14 and check
for a broken
wire or a
loose connec-
tion between
components
Problem
solved