Toshiba FC-22 manual Uneven pitch and blur Symptoms

(2) Uneven pitch and blur
<Symptoms>			Feeding
Condition	Location	Phenomenon	direction
All modes	Occurs cyclically at right	Uneven pitch
	angles to paper feeding
	direction

Defect area	Step		Cause		Check item
		Main-Classification	Sub-Classification	Specific-Classification
	1				Output built-in halftone pattern on A3/LD.
Abnormal paper	2	Paper transport	Low speed	Adjustment defect	Check grid pattern.
transport speed		speed in
		registration	Low speed	Registration roller
		section		aging change
			Low speed	Registration roller	Check condition of registration rubber roller
				life worn out	surface.
			High speed	Adjustment defect	Check grid pattern.
	3	Paper transport	High speed	Adjustment defect	Check pattern.
		speed in fuser unit
					Feed the paper with the front door open and
					check the paper transport between transfer
					belt and fuser unit.
Drum drive system	4	Drum	Surface condition		Check pattern.
				Damage	Check drum surface.
				Attached foreign	Check drum surface.
				matter
	5	Drum rotation	Unstable	Motor abnormal	Run operation check in test mode.
				Control circuit	Run operation check in test mode.
				abnormal
		Drum motor	Inadequate	Adjustment defect	Re-check values set for drum motor rotaion
		rotation speed			speed.
		Drum coupling	Loose coupling		Check pattern.
			Damaged
			Deformation
Transfer belt system	6	Drive unit	Timing belt	Tension looseness	Check pattern.
	7	Transfer belt	Deformation or		Check pattern.
			damage		Condition of transfer belt edge.
		Drive roller	Slipping	Stain	Check pattern.
					Check condition of roller surface.
		Large driving load	Used toner	Over capacity	Check pattern.
			Cleaning blade	Peeling
Laser optical unit	8	Polygonal mirror	Surface inclined	Deformation	Check pattern.

FC-22 TROUBLESHOOTING 4 - 56 January 2000 © TOSHIBA TEC