Tektronix Phaser 550 Service Manual page 229

B
Test Prints
Contamination of one color by another
This is most noticeable on solid primary fills. This is caused by a
defective photoconductive cleaning blade. The blade is not
scraping off all of the untransferred toner from the previous pass
of the photoconductive belt to the accumulator belt prior to the
next toner's transfer to the photoconductive belt. Replacing the
imaging unit corrects this problem.
Rarely, a sheet of paper can become folded and jam in the
imaging unit, smudging the image.
A single color is cut off, with a jagged edge, on either the left
or right side.
The toner cartridge above the missing color is keeping that
color's toner cartridge from fully opening its door.
If the symptom appears in yellow, fix or replace the black toner
cartridge.
If the symptom appears in magenta, fix or replace the yellow
toner cartridge.
If the symptom appears in cyan, fix or replace the black magenta
cartridge.
Service Manual B-7