CHAPTER 4 IMAGE TROUBLESHOOTING
4-15
20. Unsharp (Unforcussed) image
Action
1. Check if the
copyboard copy is
wrapped.
2. Explain to the user
how to place the origi-
nal on the copyboard.
Clean the copyboard
glass.
Check the lens drive
unit.
Adjust the distance be-
tween the No.1 mirror
mount and the mirror 2
mount and the service
mode C7, C8, C10 and
C11.
Clean the scanning lamp,
reflectors, mirrors, lens,
and dust-proofing glass.
Result
No
Yes
No
No
Yes
Check
Is the original lying flat on the glass?
Is any oil or other substance adhering to
the copyboard glass?
Set the power switch OFF and then ON
again. Does the lens move smoothly?
Is the horizontal reproduction ratio within
the standard for a DIRECT copy?
Procedure
1
2
3
4
Cause/Problem
area
Original
Copyboard
glass
Lens drive
assembly
Mirror
position
Dirt on the
scanner
21. Blank image
Action
Insert the drum unit.
Insert the developing as-
sembly.
1. Check if the photosen-
sitive drum rotates
smoothly.
2. Check the drum drive
unit.
Replace the DC control-
ler PCB.
Replace the high-voltage
transformer (HVT).
Result
No
No
No
No
Yes
Check
Is the drum unit inserted?
Is the developing assembly inserted?
Does the photosensitive drum rotate dur-
ing copying?
Set the meter to the 30VDC range and
measure the voltage between J307-1 (+)
(GRDON) and J307-7 (-) of the DC con-
troller PCB. Is the voltage approx. 15V
when the scanner is advancing and 0V at
other times?
Procedure
1
2
3
4
Cause/Problem
area
Drum unit
Developing
assembly
Drum drive
unit
DC controller
PCB
High-voltage
transformer
(HVT)