6-8
Phaser 440 Color Printer
6
Troubleshooting
Printing and print quality problems
Print problems fall into the following five categories:
■
Streaks or lines in the prints
■
No printing
■
Printing (density) too light or too dark
■
Image is offset or cutoff
■
Wrinkling
■
Misregistration
Streaks or lines parallel to the long axis of printing
1.
Clean the thermal head. This is discussed in the Chapter 7 topic
“Cleaning.”
2.
If the streak (a dot-wide line of no printing) runs the entire length of
the page, the thermal head may have a defective printing element. In
this case, replace the printer.
3.
Ensure that the serial-numbered thermal head ROM on the engine
control board matches the serial number on the thermal head. The
ROM contains thermal head normalization data that compensates for
the slight resistance variations from thermal head element to element.
Streaks or lines
parallel to the short axis of printing
1.
Inspect the paper drive system. Ensure that the paper transport
system (gears, belts and rollers) rotates smoothly.
2.
Ensure that the timing belts are properly tensioned.
3.
If this does not correct the problem, then replace the print engine.
White portion of print is colored
1.
If the thermal head is transferring dye to the paper when it shouldn't,
the thermal head is too hot. Thermal head voltage control may be bad;
check the power supply thermal head voltage. Measure the power
being supplied to the thermal head (refer to the topic Chapter 9 topic
“Adjusting the thermal head voltage” on page 9-2.
2.
Replace the print engine.
Required tools
■
#1 POSIDRIV
screwdriver
■
Volt-ohm
-meter (VOM)
