Canon FY8-13EX-000, NP6218 service manual The copy has poor sharpness, 10-61

CHAPTER 10 TROUBLESHOOTING

20. The copy has poor sharpness.

Cause	Step	Checks	Results		Action
Original	1	Is the original off the glass	YES	1.	Check the copyboard
		surface?			cover for warping.
				2. Advise the user how
					to place an original.
Copyboard	2	Is copyboard glass stained with	YES	•	Clean the copyboard
glass		oil? Is the copyboard glass			glass.
		attached correctly?		•	Re-attach the
					copyboard glass.
Lens drive	3	Turn off and on the power switch.	NO	Check the lens drive
assembly		Does the lens move smoothly?		assembly.
Transfer	4	Execute ‘No. 403’ in service mode	YES	End.
charging roller		(transfer roller cleaning). Is the
		problem corrected?
	5	Is the transfer charging roller	NO	Re-insert the charging
		securely inserted?		roller.
	6	Is dirt, cracks, or scratches noted	YES	Replace the transfer
		on the transfer charging roller?		charging roller.
	7	Are the position and condition of	NO	Correct or replace the
		the transfer roller pressure spring		spring.
		normal?
Drum cartridge	8	Is the drum cartridge securely	NO	Replace the drum
Developing		set? (Check if the spacer for the		cartridge or the
assembly		developing assembly is in contact		developing assembly.
		with the photosensitive drum
		under pressure.)
Development	9	Is the development bias generated	NO	• Replace the composite
bias		normally?			power supply PCB.
					(Replace the DC con
					troller PCB.)
Mirror	10	Is the horizontal reproduction ratio	NO	Adjust the position
		in Direct with on specification?		between No. 1 and No. 2
				mirrors.
Scanner			YES	Clean the scanning
				lamp, reflecting plate,
				mirrors, lens, and dust-
				proofing glass.

COPYRIGHT © 1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON) 10-61