Print Quality Problems; Completely Blank Printout; All-Black Printout - Kyocera Mita FS-6750 Service Manual

6.5

Print quality problems

Print quality problems range from uneven tone to completely blank output. The
troubleshooting procedure for each type of problem is given below.

Completely blank printout

Checkpoint
Check the developer.
Check the transfer bias
potential.
Check the laser scanner unit. • The scanner components within the scanner may be dis-
Defective main board [KP-
903].

All-black printout

Check point
Check the main charger unit • Open the printer side cover and check that the drum unit
Check the drum bias.
Check high voltage potential
at the high voltage unit.
Defective main board [KP-
903].
Suggested remedy
• Check that the developer is inserted correctly.
• Check that the toner on the magnet roller surface.
• Check the transfer bias output on the high voltage unit.
This requires removal of the left cover and the test equip-
ment. Replace the high voltage unit if high voltage poten-
tial is not available on the board.
ordered. Replace the laser scanner unit.
• Replace the main board [KP-903].
Suggested remedy
is correctly seated. Check for poor contact of the main
charger terminal between the main charger unit and the
drum unit.
• Make sure the bias from the high voltage unit correctly
arrives at the drum unit.
• Check the high voltage output on the high voltage unit.
Replace the high voltage unit if high voltage potential is
not available on the board.
• Replace the main board [KP-903].
6-22
Troubleshooting
Print quality problems
FS-6750