80TroubleshootingThis chapter includes these sections:• MPU failures• FIP module failures• Power supply failures• Fan failures• HIM/MIM failures• Configuration system problems• Password loss• Cooling system failure• Interface module, cable, and connection failure• Software upgrade failures• Application file missing errorsNOTE:The barcode stuck on the router chassis contains production and servicing information. Before you returna faulty router for serving, provide the barcode information of the router to your local sales agent.MPU failuresRUN LED is offWhen the RUN LED of the MPU is off, it indicates that the MPU is powered off or faulty. For moreinformation about the RUN LED, see “Appendix C LEDs.”Follow these steps to troubleshoot the MPU failure:Step1 Check whether the MPU is plugged in a right slot.• An RPE-X1 MPU must be plugged in slot 0 or slot 1.• An RSE-X1 MPU must be plugged in slot 1 or slot 2.Step2 Check whether the router is powered on normally. A green POWER LED indicates that the router ispowered on normally.Step3 If the cause cannot be located in the steps above and the problem persists, contact your local salesagent.RUN LED fast flashesFive minutes after the router is powered on or the MPU is plugged into the router, if the RUN LED of theMPU still fast flashes at 8 Hz, it indicates that the MPU application program fails to start or the MPU isfaulty.Follow these steps to troubleshoot the MPU failure:
