Printing And Print Quality Problems; Blank Print; All-Black Print - Tektronix Z740/N - Phaser 740 Color Laser Printer Service Manual

Printing and print quality problems

Required tools
#1 Phillips screwdriver
Volt-ohm - meter (VOM)
Note Refer to the later topic, "Test Prints" on page 103 for many examples
of print defects.

Blank print

1.
Press, and hold for 4 seconds, the rear panel Test Print button to determine if
the print engine will image at all. It should produce a parallel line print. If
the engine produces a good parallel line print, the print engine is good and
the image processor board is bad. If you get a blank print then the following
items may be defective. The engine test print feature only works if a paper
tray is installed in the top tray slot.
2.
Replace the laser unit.
3. Replace the imaging unit.
4. Determine if the cartridge selector is pushing the toner cartridges into
contact with the photoconductive drum.
5.
Replace the toner cartridge drive unit.
6.
Replace the cartridge sector/eject unit.
7.
Replace the engine driver board.

All-black print

1.
Entire print, including margins is black. Remove and reinstall the main
charge grid.
2.
Inspect the main charge grid for a broken corona wire. Replace the main
charge grid.
3.
Replace the high-voltage board
4. Margins are white, print is black. Replace the image processor board.
5. Replace the engine control board.
Conductive grease
Ruler
Service Guide
47