Xerox 4400DT - Phaser B/W Laser Printer Service Manual page 69

Close Front/Rear Cover Troubleshooting Procedure (cont'd.)
Step Actions and Questions
4 1. Switch the printer power OFF.
2. Remove the Left Interface Cover (RRP 1.1 on
page 6-6), Left Cover (RRP 1.2 on
Left Plate (RRP 1.11 on
3. Disconnect P/J30 from the Engine Logic Board.
4. Measure the resistance between pins 1 and 2 on the
disconnected plug as you open and close the Rear
Cover.
Is there continuity when the Rear Cover is
closed and infinity when the Rear Cover is
open?
5 Open and close the Front Cover.
Does the message on the display alternate
between "Closed" and "Open" as you open and
close the Front Cover?
6 1. Switch the printer power OFF.
2. Remove the Left Interface Cover (RRP 1.1 on
page 6-6), Left Cover (RRP 1.2 on
Left Plate (RRP 1.11 on
3. Disconnect P/J284 from the LVPS PWB.
4. Measure the resistance between pins 1 and 2 on the
disconnected plug as you open and close the Front
Cover.
Is there continuity when the Front Cover is
closed and infinity when the Front Cover is
open?
7 1. Connect P/J284 to the LVPS.
2. Switch the printer power-on.
3. On the Engine Logic Board, check the voltage
between P/J28 pin 1 and frame ground.
Is the voltage +24 VDC?
2-32
page 6-7), and the
page 6-16).
page 6-7), and the
page 6-16).
Phaser 4400 Laser Printer Service Manual
Yes No
Replace the Check the
Engine Logic wiring be-
Board (RRP tween P/J30
9.3 on and the Rear
page 6-89). Cover Inter-
lock Switch.
Repair or re-
place the wir-
ing or inter-
lock switch
(RRP 9.10
on
page
as required.
Replace the Go to step 6.
Engine Logic
Board (RRP
9.3 on
page 6-89).
Go to step 7. Check the
wiring
between
P/J284 and
the Front
Cover
Interlock
Switch.
Repair or
replace the
wiring or
interlock
switch (RRP
9.9 on
page
as required.
Replace the Replace the
Engine Logic LVPS (RRP
Board (RRP 9.5 on
9.3 on page
page 6-89).
6-97)
6-96)
6-91).