Muratec MFX-2550 Field Engineering Manual page 242

Printer section
Section Step Check item
Drum cartridge 1
Circuit boards 2
3
4.5.4 Low image density / rough image
Scanner section
Section Step Check item
Scanner section 1
(Front side)
2
3
4
5
6
Is the grid bias, wire electrode contact
terminal, or drum ground contact
terminal dirty or deformed?
Are the connections from LPH to
high-voltage board, and from high-
voltage board to main control board
in good condition?
(Check plugs firmly plugged and
snapped harness)
Is the trouble settled with above
steps?
Is the scanner drive transmission
mechanism in good condition?
Are the document glass, back plate
and ADF glass dirty?
Are the mirrors and lens dirty?
Is the platen cover floating by copying
a thick volume?
Do the connection from CCD 
Scanner board  Main control board
 LPH board  LPH connect board
 LED unit remain intact?
Is the trouble settled with above
steps?
Result Remedy
YES Clean. / Replace.
NO Reconnect. / Replace harness.
NO 1. Replace drum cartridge.
2. Replace LPH.
3. Replace LPH connect board.
4. Replace LPH board.
5. Replace main control board.
6. Replace high-voltage power
board.
Result Remedy
NO Check and change as
necessary.
YES Clean the parts, and adjust the
background level.
YES Clean or replace the parts, and
adjust the background level.
Copy with opened platen cover.
YES
NO Reconnect / Replace harness
NO 1. Replace scanner board.
2. Replace main control board.
3. Replace LPH board.
4. Replace LPH connect board.
5. Replace LPH.
4-29