Sharp SF-2040 Service Manual page 106

(Trouble codes and countermeasures)
Trouble code Sub code
F2 31
F2 32
F2 35
Content
Image exposure sensor error
Photoconductor surface
reflection detection error
Copier operation halt when
sensing
Drum mark sensor trouble
Surface level and drum mark
sensing abnormality
Copier operation halt when
sensing.
Process control operation
failure
When 1 or 2 is detected,
process control is fixed to the
reference condition.
In case of an accidental
trouble caused by the change
in environments (temperature,
humidity), if the inside state of
the machine recovers, then
the trouble will be cleared.
Possible cause
Dirt on the image density sensor (ID)
Dirt on the drum surface by
incomplete cleaning
Image density sensor (ID) sensing
level is not adjusted.
Image density sensor (ID) PWB
trouble
* Process control VR PWB trouble
Dirt on the drum mark sensor (DM)
Dirt on the drum surface by incomplete
cleaning
Drum mark sensor (DM) sensing level
is not adjusted.
Improper drum (drum without mark)
* Drum mark sensor (DM) PWB
trouble
* Process control VR PWB trouble
1 Image density is too high to be
corrected. (When executing
simulation No. 44-6)
Developer/toner density changes
greatly.
Humidity and temperature is low.
2 Image density is too low to be
corrected.
(When executing simulation No.
44-6)
Developer/toner density changes
greatly.
Humidity and temperature change
greatly.
7 – 24
Countermeasure
Clean the image density sensor and
its peripheral. Use soft cloth
immersed in water or alcohol to clean
the sensor surface.
Check the cleaning blade and the
photoconductor drum surface and
replace them if necessary.
Execute simulation No. 44-3. (Set to
204±10 with VR2.)
Clean the drum mark sensor (DM)
and its peripheral. Use soft cloth
immersed in water or alcohol to clean
the sensor surface.
Check the cleaning blade and the
photoconductor drum surface, and
replace them if necessary.
Execute simulation No. 44-2. (Set to
204±10 with VR1.)
Check the developer unit.
Visually check the pressure contact
and the lock state.
•
Check the high voltage output.
Simulation No. 44-11.
NORMAL: –860V
PATCH: –610V
Simulation No. 8-1
DV BIAS: –300V
•
Developer stirring
Simulation No. 25-1.
Replace the developer.