Phaser 3140/3155/3160 Printer Service Manual 2-17Theory of OperationExit SensorThe Exit Sensor, located on the Fuser, detects the media as it exits the Fuser.The CPU monitors the on/off timing of the Exit Sensor signal and determinesnormal operation or the presence of a jam (Jam2). If a paper jam is detected, thered LED on the Control Panel illuminates.Out Bin Full SensorThe Out Bin Full Sensor detects when the output tray is full If the sensor detectsthe output tray is full, the red LED on the Control Panel illuminates.Front Cover InterlockThe Front Cover Interlock switch is located on the Power Supply. When the FrontCover is open, the +24 V that is supplied to the Motor, solenoids, Fan, Laser Unit,and the high voltage circuitry is cut off. When the Front Cover is open, the StatusLED changes to red.Driving CircuitFan and Solenoid DrivingThe Fan, Pick Up Solenoid, and the Manual Feed Solenoid are driven by signalsfrom the Controller Board. A diode protects the driving transistor from the noisepulse that is created when the solenoid is de-energizing.Motor DrivingThe Controller Board contains the motor interface circuits, and the Drive Assemblycontains a motor control board with a driver IC.
