3-20 Phaser 4400 Laser Printer Service ManualRegistration SensorRegistration Sensor Troubleshooting ProcedureStep Actions and Questions Yes No1 1. Enter Service Diagnostics and select Sensor Tests.2. Scroll to Registration Sensor and press OK.3. Open the Front Cover.4. With a strip of paper, actuate and deactuate theRegistration Sensor.Does the message on the Front Panel displaychange from ìWith Paperî to ìWithout Paperîas you press and release the actuator?It appearsthat theRegistrationSensor isworkingcorrectly. If aproblempersists,replace theEngine LogicBoard (RRP9.3 onpage 6-89).Go to step 2.2 Does the actuator move freely and is it in goodcondition (not broken or damaged)?Go to step 3. Replace theRegistrationActuator(RRP 5.3 onpage 6-60).3 1. Switch the printer power OFF.2. Remove the Left Interface Cover (RRP 1.1 onpage 6-6), Left Cover (RRP 1.2 on page 6-7), and theLeft Plate (RRP 1.11 on page 6-16).3. Switch the printer power ON.4. On the Engine Logic Board, measure the voltagebetween P/J23 pin 11 and frame ground.Is the voltage +3.3 VDC with the RegistrationSensor deactuated, and 0.0 VDC with theRegistration Sensor actuated?Replace theEngine LogicBoard (RRP9.3 onpage 6-89).Go to step 4.4 1. Switch the printer power OFF.2. Remove the Left Front Cover (RRP 1.7 onpage 6-12).3. Switch the printer power ON.4. On the Connector PWB, measure the voltagebetween P/J43 pin 5 and frame ground.Is the voltage +3.3 VDC with the RegistrationSensor deactuated, and 0.0 VDC with theRegistration Sensor actuated?Replace theConnectorPWB (RRP9.7 onpage 6-94).Go to step 5.5 Check the voltage between P/J43 pin 3 and frameground.Is the voltage 1.2 VDC?Replace theRegistrationSensor (RRP5.4 onpage 6-61).Replace theEngine LogicBoard (RRP9.3 onpage 6-89).
