Tektronix Phaser 840, Service Manual

Page: 79 / 207

68 Phaser 840 and 850 Color Printers
Missing ink or light colored ink band running length of print
Possible missing or weak jet.
1. Print the Service Test Print 2 “Weak
Jet” to determine which jet is not
performing. If not already tried,
perform up to three printhead
cleaning cycles to try to clean a
clogged jet.
2.
Refer to the topic “Evaluating the
printhead and cap/wipe/purge
system” on page 80. A properly
functioning printhead maintenance
system is essential for proper
printhead operation.
3. If necessary, turn off the printer and
allow the printhead to cool for
4 hours.
4. If weak or missing jet cannot be
recovered, 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 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. Refer to the topic “Evaluating the
printhead and cap/wipe/purge
system” on page 80. A properly
functioning printhead maintenance
system is essential for proper
printhead operation.
3.
Perform the procedure, “Printhead-
to-drum spacing adjustment
(Phaser 840 printer)” on page 102
and “Transfix roller pressure spring
adjustment” on page 110.
4. Replace the printhead.
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