Tektronix Phaser 840, Service Manual

Page: 151 / 207

140 Phaser 840 and 850 Color Printers
Drum position sensor assembly (Phaser 850)
1. Remove the left cover.
2. Remove the top cover.
Caution
Unhook the head-tilt spring to avoid possible damage to the
printhead and drum.
3. Disconnect the drum position encoder sensor cable at the drum position
assembly.
4.
Remove the clear plastic dust cover from the drum position assembly.
5. Precisely mark the end of the drum shaft where it aligns with the home
reference line on the encoder so that the encoder can be reinstalled in
the same position on the shaft. This is not necessary if you are also
replacing the drum (as part of the drum/transfix assembly).
6.
Rotate the tilt gear to orient the gear’s missing teeth to the drum
position sensor assembly’s rear mounting screw.
Marking the shaft for drum home alignment
840-4-77
Mark the drum shaft where
it aligns with the home
reference mark
Drum position
encoder wheel