4-12 Phaser 7400 Color Printer Service ManualEngine Power-Up Sequence (BIST)The following checks are made by the printer’s firmware at each power-up.1. Engine Control Board logic check2. Imaging Unit (Missing, NVRAM (CRUM) Error, CRUM ID, Life Over)3. Fuser (Missing, NVRAM (CRUM) Error, Life Over)4. Toner Cartridge (Missing, Life Over)5. Transfer Roller (Missing, Life Over)6. ADC Sensor (Error)7. All paper sensor (Jam)8. Door(s) (Open)9. Environment Sensor (Error)10. NVRAM (NVRAM error)11. Image Processor Board POST Diagnostic check4 Does the error persist? Replace theControl Panel(page 8-111).Complete.5 Check voltages at the Engine Control Board.Disconnect the POWER connector.Is the voltage at each POWER pin correct?Replace theEngine ControlBoard(page 8-112).Go to Step 7.6 Check the POWER connector.Reconnect the POWER Connector and cycleprinter power.Does the error persist?Replace the LVPS(page 8-121).Complete.7 Check voltages at the Image ProccesorBoard.Disconnect the CUIF connector.Is the voltage at each POWER pin correct?Replace theImage ProcessorBoard(page 8-113).Go to Step 9.8 Check voltages at the Engine Control Board.Disconnect the POWER connector.Is the voltage at each POWER pin correct?Replace theEngine ControlBoard(page 8-112).Replace theLVPS(page 8-121).Troubleshooting Procedure Table
