Tektronix PHASER 380, Service Manual

Page: 300 / 346

9-20
Phaser 380 Color Printer
9
Checks and Adjustments
Drum position encoder gap
This procedure ensures that the drum position sensor assembly’s encoder wheel
rotates freely inside the gap of the drum position sensor without the encoder
wheel’s disk touching the sensor. If the disk touches the sensor, it can abrade the
disk and result in erroneous drum position readings.
1. Turn off the printer. Remove the left panel as described in the topic
“Cabinet panels and covers” on page 8-4.
2.
Remove the drum encoder’s dust cover.
3. Gently move the retaining spring out of the drum position sensor
assembly’s encoder wheel groove. This ensures that the encoder
wheel is not tensioned and slides easily on the drum shaft.
4.
Through the access hole in the drum position sensor assembly,
position the encoder gap tool on the drum shaft.
5. Slide the drum position sensor assembly’s encoder wheel on the drum
shaft until it butts firmly against the encoder gap tool.
6.
Holding the gap tool in place, with a small, flatblade screwdriver,
slide the encoder wheel’s retaining spring into the encoder wheel’s
groove. Rotate the drum to help work the spring into the groove.
7. Remove the gap tool. Visually check to ensure the encoder disk is
centered in the two interrupt-style drum sensors.
8. Reassemble the printer and make a test print.