Xerox Phaser 790 - Page 126

10/00
2-112
Phaser 790/DocuColor 2006
007-712
Initial Issue
Status Indicator RAPs
007-712 Tray 2 Paper Size Not Detected RAP
The Control Logic detected that the wrong size paper is feeding from Tray 2.
Initial Actions
Ensure that the paper in Tray 2 is properly installed and that the tray side and end guides are
positioned to touch the paper in the tray.
Procedure
Switch off the power. Disconnect the Power Cord. Remove the Size Switch PWB (PL 13.3).
Place the Size Switch PWB so that it does not short circuit to the machine frame. Connect the
Power Cord. Disconnect PJ 235 from the Size Switch PWB. Switch on the power. There is +5
VDC from J 235 pin 1 to machine ground.
YN
Go to Flag 2. Check the wires for an open or a short circuit to ground. The wires are
good.
YN
Repair the wires.
Replace the MCU PWB (PL 11.2).
Connect PJ 235 on the Size Switch PWB. Actuate and hold switches SW1 and SW3 on the
Size Switch PWB. There is +1.57 ±0.10 VDC from J 235 pin 2 to machine ground.
YN
Go to Flag 1. Check the wires for an open or a short circuit to ground. The wires are
good.
YN
Repair the wires.
Replace the Size Switch PWB (PL 13.3).
Actuate and hold switches SW2 and SW4 on the Size Switch PWB. There is +3.13 ±0.10
VDC from J 235 pin 2 to machine ground.
YN
Go to Flag 1. Check the wires for an open or a short circuit to ground. The wires are
good.
YN
Repair the wires.
Replace the Size Switch PWB (PL 13.3).
Replace the MCU PWB (PL 11.2).
Table 1 Tray 2 Size Sensing Switch PWB
PAPER SIZE PAPER SIZE SW
ANALOG
VOLTAGE OUT
SW1 SW2 SW3 SW4
Tray Out OFF OFF OFF OFF (+) 4.76 VDC
Ledger (SEF) OFF ON OFF OFF (+) 3.45 VDC
A3 (SEF) ON OFF ON OFF (+) 1.57 VDC
Letter (LEF) OFF ON ON ON (+) 2.49 VDC
B5 (LEF) OFF ON OFF ON (+) 3.13 VDC
Legal (SEF) OFF OFF ON OFF (+) 4.09 VDC
A4 (LEF) OFF OFF ON ON (+) 3.77 VDC
B4 (SEF) OFF ON ON OFF (+) 2.81 VDC
A
A