Video problemsUse this information to solve video problems.See “Monitor and video problems” on page 162.Solving power problemsUse this information to solve power problems.About this taskPower problems can be difficult to solve. For example, a short circuit can existanywhere on any of the power distribution buses. Usually, a short circuit willcause the power subsystem to shut down because of an overcurrent condition. Todiagnose a power problem, use the following general procedure:Procedure1. Turn off the server and disconnect all power cords.2. Check for loose cables in the power subsystem. Also check for short circuits, forexample, if a loose screw is causing a short circuit on a circuit board.3. Check the lit LEDs on the light path diagnostics panel (see “Light pathdiagnostics LEDs” on page 137).4. If the check log LED on the light path diagnostics panel is lit, check the IMMevent log for faulty Pwr rail and complete the following steps. Table 17identifies the components that are associated with each Pwr rail and the orderin which to troubleshoot the components.a. Disconnect the cables and power cords to all internal and external devices(see “Internal cable routing and connectors” on page 197). Leave thepower-supply cords connected.b. For Pwr rail 1 error, complete the following steps:1) (Trained technician only) Replace the system board.2) (Trained technician only) Replace the microprocessor.c. For other rail errors (Pwr rail 1 error, see step 4b), remove each componentthat is associated with the faulty Pwr rail, one at a time, in the sequenceindicated in Table 17, restarting the server each time, until the cause of theovercurrent condition is identified.Table 17. Components associated with power rail errorsPwr rail error in the IMM event log ComponentsPwr rail 1 error v Microprocessor 1Pwr rail 2 error v Microprocessor 2Pwr rail 3 error v Optional adapter (if one is installed) in PCIriser-card assembly 1v PCI riser-card assembly 1v ServeRAID SAS/SATA adapterv DIMMs 1 through 6Chapter 4. Troubleshooting 175
