2-88 Service Manual
5021-0XX
5 If paper tray is removed,
set paper tray for desired
paper size and insert paper
tray into printer. Using table
below, check for proper
paper size sensor action by
taking voltage readings
between ground and
DCN19 pins 2 though 4. Is
paper size sensor working
properly?
Replace I/O
board. See “I/O
board removal”
on page 4-70. If
problem
persists, replace
engine controller
board. See
“Engine
controller
board removal”
on page 4-55.
Go to step 6.
6 Check cable for continuity
between I/O board DCN19
and paper size sensor. Also
check for shorted pins. Is
cable okay?
Replace paper
size sensor. See
“Left tray guide
assembly
removal” on
page 4-65.
Replace cable.
Paper tray setting
DCN19 (all voltages measured
from pin to ground)
Standard tray
pin 2pin 3pin 4pin 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
Step Questions / actions Yes No
