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Service Guide
49
3.
Dark rectangular marks on transparency film can be caused by an
accumulation of paper dust and oil on the feed rollers. Run 2 or 3
sheets of blank paper through the printer to clean the rollers or
manually clean the rollers.
4.
Replace the power control board.
5.
Non-functioning printhead data cable. Replace the main board.
6.
Replace the printhead.
Color is uneven
This may be due to poor thermal
regulation in the printer, resulting in
uneven heating of the printhead, which
in turn results in uneven ink drop
jetting.
1.
Clean the wiper blade and the wick
of the drum maintenance drawer.
Inspect the operation of the drum
maintenance cam roller and the left
and right cam actuators it pushes
against.
2.
Perform the procedure,
“Printhead-to-drum spacing
adjustment” on page 66 and
“Transfix roller pressure spring
adjustment” on page 72.
3.
Replace the printhead.
Not printing
The printer processes a sheet of paper, but no image is printed on it.
1.
No drive voltages to the printhead. Check for a loose connector
leading to the printhead.
2.
Replace the power control board.
3.
Replace the printhead.
Printing too light or too dark
1.
Make sure the printer is correctly reading the type of tray installed and
that the tray is correctly set for the media loaded in it. Printing on
paper in transparency mode significantly darkens a print. Try a
different color correction setting.
2.
Perform the procedure, “Printhead-to-drum spacing adjustment” on
page 66.
0388-45
Summary of Contents for Phaser 840
Page 46: ...36 Phaser 840 Color Printer ...
Page 95: ...Service Guide 85 Clearing PostScript NVRAM menu item ...
Page 96: ...86 Phaser 840 Color Printer ...
Page 121: ...Service Guide 111 Figure 1 Cabinet FRUs 7 5 6 8 1 2 4 0388 21 3 ...
Page 125: ...Service Guide 115 Figure 3 Paper path FRUs 0388 16 2 1 5 11 10 9 12 6 4 3 7 13 8 ...
Page 127: ...Service Guide 117 Figure 4 Motors and fans FRUs 0388 14 7 4 3 5 6 2 1 ...
Page 129: ...Service Guide 119 Figure 5 Circuit boards FRUs 4 3 5 2 1 9 7 6 8 10 11 13 0388 13 12 ...
Page 131: ...Service Guide 121 Figure 6 Solenoids and clutches FRUs 4 5 3 2 1 0388 23 ...
Page 137: ...Service Guide 127 Figure 9 High capacity PaperTray 0388 65a 1 2 ...
Page 142: ...132 Phaser 840 Color Printer ...
Page 154: ...144 Phaser 840 Color Printer ...