Xerox 5400N - Phaser B/W Laser Printer, Service Quick Reference Manual

Page: 152 / 503

Phaser 5400 Laser Printer Service Guide 123
RAP 45 Malfunctioning LCD/LED
The Control Panel LCD is erratic.
Table 71 Malfunctioning LCD/LED Troubleshooting Procedure
Step Actions and Questions Yes No
1 PROCEDURE
1. Switch printer power OFF.
2. Remove any options connected to the System
Controller Board.
3. Disconnect P/J18 from the System Controller Board.
4. Switch printer power ON.
5. On the System Controller Board, measure the
following voltages between P/J18 and frame ground.
Note: Refer to Table 72 for what should be expected.
Do all the voltages listed in the column “With
P/J18 Disconnected” measure correctly?
Go to
Step 8. Go to
Step 2.
2
+3.3 VDC AT P/J3 ON SYSTEM CONTROLLER
BOARD
Measure the voltage on P/J3-1 and P/J3-2.
Does the voltage at P/J3-1 and P/J3-2 measure
+3.3 VDC?
Go to
Step 5. Go to
Step 3.
3 +3.3 VDC NO LOAD CHECK ON SYSTEM
CONTROLLER BOARD
1. Switch printer power OFF.
2. Disconnect P/J3 from the System Controller Board.
3. Switch printer power ON.
4. Measure the voltage between pins 1 and 2 on the
disconnected plug.
Does the voltage between pins 1 and 2 on the
disconnected plug m3.3 VDC?
Replace the
System
Controller
Board
[RRP 8.1,
page 305 ].
Go to
Step 4.
4 LVPS P/J163 VOLTAGE CHECK
Measure the voltage between P/J163-1 and P/J163-2.
Does the voltage between P/J163-1 and 163-2
m3.3 VDC?
Repair or
replace the
harness
between the
LVPS and
the System
Controller
Board
[PL 9.2,
page 406 ].
Replace the
LVPS
[RRP 8.6,
page 312 ].
5 SYSTEM CONTROLLER BOARD +5 VDC CHECK
On the System Controller Board, measure the voltage
on P/J13-1 and P/J13-2.
Does the voltage between P/J13-1 and P/J13-2
m5.0 VDC?
Go to
Step 8. Go to
Step 6.