Phaser 7500 Printer Service Manual 2-33
Theory of Operation
Primary Transfer
1st BTR Retract Clutch (PL3.2.12)
The 1st BTR Retract Clutch transfers the drive of the Fuser Drive Motor Assembly to 
the 1st BTR Roll (Y), 1st BTR Roll (M), and 1st BTR Roll (C) that are part of the IBT 
Belt Unit.
1st BTR Contact Retract Sensor (PL3.2.17)
The 1st BTR Contact Retract Sensor detects the position of the 1st BTR Roll (Y), 1st 
BTR Roll (M), and 1st BTR Roll (C) (whether or not they are in contact with the belt). 
In contact with belt: Sensor blocked
s7500-369
1st BTR Roller
IBT Belt Home 
Position Sensor
IBT Belt Unit
1st BTR Contact
Retract Clutch
1st BTR Contact
Retract Sensor
Belt
MOB ADC Assembly
IBT Belt Cleaner Assembly
MOB Sensor Out
MOB Sensor In
ADC Sensor Assembly
IBT Belt Home 
Position Sensor
Environment Sensor