Xerox Phaser 790 - Page 124

10/00
2-110
Phaser 790/DocuColor 2006
007-711
Initial Issue
Status Indicator RAPs
007-711 Tray 1 Paper Size Not Detected RAP
The Control Logic detected that the wrong size paper is feeding from Tray 1.
Initial Actions
Ensure that the paper in Tray 1 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 High Voltage Power Supply (PL
11.1). Remove the Tray 1 Size Bracket Assembly (PL 3.1). Remove the Size Switch PWB (PL
3.1) from the Bracket Assembly. Place the Size Switch PWB so that it does not short circuit to
the machine frame. Install the Tray 1 Size Switch Bracket. Install the High Voltage Power Sup-
ply. Connect the Power Cord. Disconnect PJ 102 from the Size Switch PWB. Switch on the
power. There is +5 VDC from J 102 pin 2 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 102 on the Size Switch PWB. Actuate and hold switches SW1 and SW2 on the
Size Switch PWB. There is +3.15 ±0.10 VDC from J 102 pin 1 to machine ground.
YN
Go go 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 3.1).
Actuate and hold switches SW3 and SW4 on the Size Switch PWB. There is +0.97 ±0.10
VDC from J 102 pin 1 to ground.
YN
Go go 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 3.1).
Replace the MCU PWB (PL 11.2).
Table 1 Tray 1 Size Sensing Switch PWB
PAPER SIZE PAPER SIZE SW
ANALOG
VOLTAGE OUT
SW1 SW2 SW3 SW4
Tray Out OFF OFF OFF OFF (+) 0.24 VDC
B5 (LEF) ON ON OFF OFF (+) 3.15 VDC
A4 (LEF) OFF ON OFF OFF (+) 1.21 VDC
Letter (LEF) ON OFF ON OFF (+) 2.67 VDC
A4 (SEF) OFF ON ON ON (+) 1.94 VDC
Legal 14” (SEF)ONONONOFF(+) 3.64 VDC
B4 (SEF) OFF ON OFF ON (+) 2.45 VDC
A3 (SEF) OFF OFF ON OFF (+) 0.73 VDC
12” x 18” (SEF) OFF OFF OFF ON (+) 0.48 VDC
Ledger (SEF) OFF OFF ON ON (+) 0.97 VDC
A
A