Lexmark 5021-0XX manual On page 4-70. If, Left tray guide

5021-0XX

Step	Questions / actions				Yes			No
5	If paper tray is removed,			Replace I/O			Go to step 6.
	set paper tray for desired			board. See “I/O
	paper size and insert paper			board removal”
	tray into printer. Using table			on page 4-70. If
	below, check for proper			problem
	paper size sensor action by			persists, replace
	taking voltage readings			engine controller
	between ground and			board. See
	DCN19 pins 2 though 4. Is			“Engine
	paper size sensor working			controller
	properly?			board removal”
				on page 4-55.
6	Check cable for continuity			Replace paper			Replace cable.
	between I/O board DCN19			size sensor. See
	and paper size sensor. Also			“Left tray guide
	check for shorted pins. Is			assembly
	cable okay?			removal” on
				page 4-65.
Paper tray setting		DCN19 (all voltages measured
		from pin to ground)
Standard tray		pin 2	pin 3		pin 4	pin 5
A4		5 VDC	5 VDC		0 VDC	5 VDC
Letter		5 VDC	0 VDC		5 VDC	5 VDC
EXE		0 VDC	5 VDC		0 VDC	5 VDC
B5J		5 VDC	0 VDC		0 VDC	5 VDC
B51		5 VDC	0 VDC		0 VDC	5 VDC
#10		0 VDC	0 VDC		0 VDC	5 VDC
DL		0 VDC	0 VDC		0 VDC	5 VDC
Legal tray		0 VDC	0 VDC		5 VDC	5 VDC

2-88Service Manual