Xerox Phaser 3120 Service Manual page 23

4.1.3 Self Diagnostic Mode
If Error code occurs due to malfunction of the printer, perform Self Diagnostic Mode to solve the problem.
The printer works only in the self-test mode to solve the malfunction problem.
To enter the self-test mode, turn the power on pressing the buttons of [Down], [Shift] and [Stop] at the same
time.
Release the button within 2 or 3 seconds if 78 shows in the DCU. If 00 shows in the DCU, press the button
[Up] or [Shift] to select the self+test , and press the button of [Enter] to operate. To stop, press the button of
[shift] and [Enter] together.
Code
00 Main Motor Operating System
Only the main motor is in operation.
01 Main High Voltage On(THV-)
-1400 voltage output by MHV terminal.
Caution : High voltage probe should be used.
02 Transfer High Voltage(-)On(THV-)
-1000 voltage output by MHV terminal.
Caution : High voltage probe should be used.
03 Transfer High Voltage (+)Reference on (THV +)
+800 voltage output by MHV terminal.
Caution : High voltage probe should be used.
04 DEV/supply High Voltage : DEV/Supply High Voltage Test.
The left one of the three LEDs in the self-test panel is on when DEV high voltage Supply
high voltage output by each HV terminal(-500V). Press the [Up] button to switch the volt-
age. The middle and right one of the three LEDs are on and -650 voltage output by DEV
HV terminal.
Caution : High voltage probe should be used.
05 LSU Operating System
The scanning motor of LSU is in operation, the right LED of the three buttons on. Press
the [Up] button to Check LD. LD is functioning and the middle button is on. If the LD is
normal, all LEDs are on.
06 Pickup clutch on
The Solenoid in the printer is in operation. To stop the operation, Press the button [shift]
and [Enter] together.
Description
TROUBLESHOOTING
Service Manual
4-3