Phaser 5400 Laser Printer Service Guide 133RAP 49 Fuser AssemblyWarning: If the printer has been switched on, the fuser may be veryhot.Table 78 Fuser Assembly Troubleshooting ProcedureStep Actions and Questions Yes No1 RESISTANCE MEASUREMENTS1. Switch printer power OFF.2. Remove the Fuser Assembly [RRP 5.1, page 288].3. Measure the resistance between pins A1 and A2, andbetween pins 1 and 4 or 2 and 4 on P174 on the FuserAssembly [see Figure 17 on page 134].Does the resistance between A1 and A2 measurebetween 10K and 350K ohms (depending on thetemperature of the fuser) and the resistancebetween pins 1 and 4 or 2 and 4 measure lessthan 5 ohms?Go toStep 2.Replace theFuserAssembly[RRP 5.1,page 288].2 ìYESî FROM STEP 1 ABOVE1. Reinstall the Fuser Assembly.2. Remove the Lower Rear Cover [RRP 1.7, page 256].3. Disconnect P/J172 from the Fuser Board.4. Ensure the Rear Cover is closed.5. Check for continuity between P172-1 and P172-3.Is there continuity between P172-1 and P172-3?Go toStep 4.Go toStep 3.3 ìNOî FROM STEP 2 ABOVE1. Remove the Right Side Cover [RRP 1.2, page 251].2. Ensure the Rear Cover is closed.3. Check for continuity between P/J172-1 and both sidesof the Rear Cover Interlock Switch.Is there continuity between P/J172-3 and bothsides of the Rear Cover Interlock Switch?Replace theFuserHarnessAssembly[PL 9.2,page 406].Replace theRear CoverInterlockSwitch[PL 9.2,page 406] orthe FuserWiringHarness[PL 9.2,page 406] asnecessary.4 ìYESî FROM STEP 2 ABOVE1. Remove the Left Side Cover [RRP 1.1, page 250] andthe Print Engine Controller Board Cover [RRP 8.5,page 310].2. Disconnect P/J17 from the Print Engine ControllerBoard.3. Check for continuity between P17-7 and P17-8.Is there continuity between P17-7 and P17-8?Go toStep 5.Replace theFuserHarnessAssembly[PL 9.2,page 406].5 ìYESî FROM STEP 4 ABOVE1. Disconnect P/J171 from the Fuser Board.2. Check for continuity between P17-3 and P171-1,P17-2 and P171-2 and P17-1 and P171-3.Is there continuity between all pins measured?Go toStep 6.Replace theFuserHarnessAssembly[PL 9.2,page 406].
