Xerox Phaser 7400 Service Manual page 311

Troubleshooting Procedure Table
5
Test the affected Paper Size Switch.
1. Disconnect P/J471.
2. Run the Service Diagnostics Paper Size
Switch Test.
Does the switches function normally? Use the
Paper Size Switch State table to verify proper
operation.
6 Check the Paper Size Switch signals.
1. Disconnet the Motor Driver Board PSIZE
connector.
2. Check voltages at these pins:
PSIZE-1 = +5 V
PSIZE-2 = +5 V
PSIZE-4 = +5 V
PSIZE-5 = +5 V
Is +5 V available at each PSIZE pin?
Universal Tray Paper Size Switch States
SW1 SW2
0 0
1 1
1 0
1 0
0 0
1 1
0 0
0 1
0 1
0 0
1 1
1 0
1 0
1 1
0 1
0 1
General Troubleshooting
SW3 SW4
0 0
1 1
1 0
0 1
1 1
1 0
1 0
1 0
1 1
0 1
0 0
0 0
1 1
0 1
0 0
0 1
Go to Step 6.
Replace the
Paper Size
Switch
(page 8-139)
Media Size
No tray installed
A/Letter (LEF)
A/Letter (SEF)
A3
A3-Nobi
A4 (LEF)
A4 (SEF)
A5
A6
B4
B5 (LEF)
B5 (SEF)
B/Tabloid
Executive
Ledger 13 in.
Legal 14 in.
Replace the
Paper Size
Switch
(page 8-139).
Replace the
Motor Driver
Board
(page 8-141).
4-15