Service Manual
6-9
Troubleshooting
6
Color is uneven
1.
The paper may be slipping in the paper clamp bar. Clean all four bar
clamps. See the Chapter 7 topic “Cleaning” on page 7-1.
2.
Check the paper clamp bar’s clamping pressure by trying to pull a
sheet of paper out of the closed clamps. If it's too low, the media could
be slipping. If the clamp springs are weak and cannot firmly hold a
sheet of media, replace the print engine.
3.
Check the timing belts for proper tension.
4.
Check for a defective stepper motor. Ensure that neither jerks,
chatters, or lugs down. If it does, replace the print engine.
5.
Check for nicks or burrs in the paper path that could impede the
loading of a sheet of media into the paper clamp bar.
6.
Perform the Chapter 9 procedure “Adjusting for color
misregistration” on page 9-6.
7.
Replace the print engine.
Not printing
The printer processes a sheet of paper, but no image is printed on it.
1.
Ensure that the thermal head temperature is correctly set for the
voltage value printed on the thermal head. Refer to the Chapter 9
topic “Adjusting the thermal head voltage” on page 9-2.
2.
Ensure that the thermal head power and data cables are properly
connected.
3.
If everything checks out in the previous steps you can assume that the
data drivers on the print engine control board are bad; replace the
print engine.
Printing too light or too dark
1.
Check that the correct paper is being used with the printing side
facing down in the paper tray.
2.
Ensure that the correct selection for paper or transparency is made at
the host. The printer cannot detect whether paper or transparency is
installed in the paper tray.
3.
Ensure that the thermal head voltage setting is correct based on the
value printed on the thermal head. Refer to the Chapter 9 topic
“Adjusting the thermal head voltage” on page 9-2
