Service manual

3-
8 QMS 3260/4032 Laser Printer - Base Engine Technical Manual
Release Version 11-97
Primary FIPS: Error Codes
3.5 Error Code U3-4
There is a problem with the Start of Scan (SOS) Sensor.
Logic Control on the MCU PWB detected that the time between signals from the Start of Scan Sensor was
shorter than specified.
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
RESET
1. Switch off printer main power.
2. Wait one minute.
3. Switch on printer main power.
Does the U3-4 error code appear?
Go to step 2 Suspect a
possible inter-
mittent prob-
lem with the
MCU PWB,
the Laser
Diode PWB,
the SOS Sen-
sor, or the
connectors
and wiring
linking these
components.
2
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 +5VDC
between J400-8 and FG?
Go to step 3 Replace the
LVPS Assem-
bly (RRP 9.2)
3
Replace the MCU PWB (RRP 9.7)
Does the U3-4 error code appear?
Replace the
ROS Assem-
bly (RRP 5.1)
Problem
solved