Service checks which involve measuring voltages on the LVPS/HVPS (low voltage power supply/
high voltage power supply board) should be performed with the printer positioned on its back side.
Note: When making voltage readings, always use frame ground unless another ground is
specified. See the wiring diagram in the back of the book for more information.
Controller board service check
Controller board service check
Warning: Do not
replace the operator
panel and controller
board at the same
time. Each card
contains the printer
settings. When either
of these cards is new,
it obtains some of the
settings from the other
card. Settings are lost
when both are new
and replaced at the
POST (Power-On Self Test)
Note: The printer should complete POST in approximately 30 seconds.
If the printer fails to display lights or activate the drive motor, fuser, or fan, then check the
following in order:
1. Power to the LVPS/HVPS
Turn the printer on and listen carefully for a click near the switch. A clicking sound
verifies that the outlet and power cables are good. Absence of a clicking sound may
indicate a lack of power supplied to the LVPS/HVPS.
2. Power from the LVPS/HVPS to the controller board
With the power on, check the LED below the right lower corner of the fan. If the LED
lights up, it indicates that power is supplied to the controller board. If the LED does not
light up, proceed to the next check item.
3. Cables correctly plugged, especially for the operator panel
The printer will not power-up without a functioning operator panel even with a lighted
LED on the controller board.
4. The controller board assembly
The LED adjacent to J12 will be illuminated if the card is powered and good.
5. The operator panel
"Operator panel service check" on page
Verify +24 V dc input from the LVPS/HVPS.
1. Turn the printer off.
2. Disconnect the LVPS/HVPS cable from the controller board at J502.
3. Turn the printer on.
4. Verify +24 V dc on positions 6, 17, and 19 of the cable connector (LVPS/HVPS). If there
is no voltage supplied on any of these positions, turn the printer off and go to step 7.
5. Verify +5 V dc on positions 1, 3, 4, 5, 11, 13 and 15 of the cable connector (LVPS/
HVPS). If there is no voltage supplied on any of these positions, turn the printer off and
go to step 7.
6. Turn the printer off. Check the continuity of the conductors of the cable and the card
connector with respect to ground. Verify that pins 10, 12, 14, 16 and 18 on the cable are
grounded. Verify the same pins on the card connector side are grounded too. If there is
no continuity on any of the card pins, verify that all the mounting screws are tight. If
there is still no connection to ground then replace the controller board. See
board removal" on page
7. Open the LVPS/HVPS and disconnect the controller board-to-LVPS/HVPS cable at
CN201.Verify continuity in each conductor of the cable. This cable is not a replaceable
part. If continuity is still not good then go to
Controller board voltage outputs
Turn the printer off, and plug the LVPS/HVPS cable into J502 of the controller board. See
the wiring diagram at the end of the manual which identifies the output voltages and
grounds for a good controller board.
Turn the printer off before plugging or unplugging any connectors.
"Dead machine service check" on