Lexmark 5021-0XX manual Transfer belt unit service check, Unit removal, Bracket, 4-45. If

			5021-0XX
990—Transfer belt unit service check
Step	Questions / actions	Yes	No
1	Open rear cover assembly	Clean belt	Go to step 2.
	and check transfer belt unit	marker area with
	markers for stains. Are	cotton cloth. If
	markers stained?	problem persists
		go to step 2.
2	Remove transfer belt unit	Replace transfer	Reinstall transfer
	and observe markers on	belt unit. See	belt unit. Go to
	side. Are belt markers	“Transfer belt	step 3.
	deformed or does transfer	unit removal”
	belt seem hard to rotate?	on page 4-7.
3	Turn printer off and remove	Go to step 4.	Properly connect
	I/O board shield. See “I/O		cables. If
	board removal” on		problem
	page 4-70for steps to		persists, go to
			step 4.
	remove I/O board shield.
	Are cables DCN13 and
	DCN16 properly connected
	to I/O board?
4	Ensure rear cover	I/O board is	Go to step 5.
	assembly and front cover	providing 5 VDC
	assembly are closed.	to marker
	Override top interlock	sensor. Replace
		transfer belt
	switch and turn printer on.
		marker sensor.
	Wait until printer displays
		Marker sensor is
	error and remove DCN16
		a part of bracket
	from I/O board. Check for 5
		assembly. See
	VDC between DCN16 pin 1
		“Bracket
	(on I/O board) and ground	assembly
	(you can touch negative	removal” on
	lead of voltmeter to metal	page 4-45. If
	bracket that holds I/O	problem
	board to obtain ground.) Is	persists, replace
		engine controller
	voltage present and
		board. See
	correct?
		“Engine
		controller
		board removal”
		on page 4-55.

Diagnostic information 2-65