Xerox Phaser 790 Service Manual page 65

005-210 Nudger Home RAP
The signal, Nudger Home (L), is not detected within 1 second after ADF Drive Motor is ener-
gized.
Procedure
Switch off the power. Remove the ADF Rear Cover. Observe the Nudger Roll as the power is
switched on. The Nudger Roll Rotates.
Y N
The ADF Drive Motor energized.
Y N
Switch off the power. Disconnect the belt from the ADF Drive Motor. Switch on the
power The ADF Drive Motor energizes.
Y N
There is +24 VDC from pin 1 and from pin 6 of J 812 to frame ground.
Y N
Replace the ADF Control PWB (PL 17.2).
Go to Flag 3. Check for broken wires, or damaged pins at J 812. If the wires
and connector are OK, replace the ADF Control PWB (PL 17.2). If the problem
continues, replace the ADF Drive Motor (PL 17.2).
Check for binding or damage to the one-way Pulleys (PL 17.2).
Check for loose or damaged Belts or Pulleys (PL 17.2, PL 17.3).
Remove the ADF Front Cover (PL 17.1). Block and unblock the Nudger Home Sensor as you
monitor the voltage from J 814 pin 8 to frame ground. The voltage is +5 VDC when the sen-
sor is blocked and less than 1 VDC when the sensor is not blocked.
Y N
The voltage is always less than 1 VDC
Y N
Disconnect P/J 713. There is +5 VDC from pin 1 to pin 3 on J 713.
Y N
There is +5 VDC from pin 9 to pin 7 on J 814
Y N
Go to Flag 2. Check for a short circuit. If the wires are OK, replace the
ADF Control PWB (PL 17.2).
Go to Flag 2. Check for an open circuit.
Replace the Nudger Home Sensor (PL 17.3).
Disconnect P/J 713. The voltage changes to +5 VDC.
Y N
Go to Flag 1. Check for a short circuit to ground. If the wire is OK, replace the ADF
Control PWB (PL 17.2).
Replace the Nudger Home Sensor (PL 17.3).
A
Initial Issue
Phaser 790/DocuColor 2006
A
Check that the Actuator for the Nudger Home Sensor (PL 17.3) is installed correctly and is free
from damage. If the Actuator is OK, replace the ADF Control PWB (PL 17.2).
10/00
2-51
Status Indicator RAPs
005-210