Phaser 4400 Laser Printer Service Manual 3-253 1. Enter Service Diagnostics and select Sensor Tests.2. Scroll to Print Cartridge Switch and press OK.3. Slide the Print Cartridge out and back in two or threetimes.Does the message on the front panel displayalternate between Installed and Not Installed asyou slide the print cartridge out and in?Replace theEngine LogicBoard (RRP9.3 onpage 6-89).Go to step 4.4 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), andLeft Plate (RRP 1.11 on page 6-16).3. Switch the printer power ON.4. On the Engine Logic Board, check the voltagebetween P/J25 pin 4 and frame ground.Is the voltage +5.0 VDC?Go to step 5. Replace theEngine LogicBoard (RRP9.3 onpage 6-89).5 1. Check the voltage between P/J25 pin 3 and frameground.2. Slide the Print Cartridge out and back in two or threetimes.Is the voltage 0.0 VDC with the Print Cartridgeout, and +5.0 VDC with the Print Cartridge in?Go to step 6. Replace thePrintCartridgeSensorAssemblytogether withthe harness(RRP 7.3,page 6-81).6 1. Check the voltage between P/J25 pin 2 and frameground.2. Slide the Print Cartridge out and back in two or threetimes.Is the voltage +3.3 VDC with the Print Cartridgeout, and 0.0 VDC with the Print Cartridge in?Replace theEngine LogicBoard (RRP9.3 onpage 6-89).Replace thePrintCartridgeSensorAssemblytogether withthe harness(RRP 7.3,page 6-81).Print Cartridge Sensor Assembly Troubleshooting Procedure (cont'd.)Step Actions and Questions Yes No
