Solving power problemsPower problems can be difficult to solve. For example, a short circuit can existanywhere on any of the power distribution buses. Usually, a short circuit will causethe power subsystem to shut down because of an overcurrent condition. Todiagnose a power problem, use the following general procedure:1. 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. If a power error LED on the system board is lit, complete the following steps;otherwise, go to step 5. See “System-board LEDs” on page 20 for the locationof the power error LEDs.a. Disconnect the cables and power cords to all internal and external devices(see “Internal cable routing and connectors” on page 136). Leave thepower-supply cords connected.b. Remove each component that is associated with the LED, one at a time,restarting the server each time, until the cause of the overcurrent conditionis identified.Important: Only a trained service technician should remove or replace aFRU, such as a microprocessor or the system board. See Chapter 4, “Partslisting, Type 7377 server,” on page 125 to determine whether a componentis a FRU.c. Replace the identified component.4. If the system-error LED on the front panel is lit, complete the following steps:a. Check the IMM-event log. To access the web interface, see “Logging on tothe Web interface” on page 245.b. If a log indicates that the power configuration is invalid, make sure that bothpower supplies installed in the server are of the same type.5. Remove the adapters and disconnect the cables and power cords to all internaland external devices until the server is at the minimum configuration that isrequired for the server to start (see “Solving undetermined problems” on page121 for the minimum configuration).6. Reconnect all power cords and turn on the server. If the server startssuccessfully, replace the adapters and devices one at a time until the problem isisolated.If the server does not start from the minimum configuration, replace the componentsin the minimum configuration one at a time until the problem is isolated.Solving Ethernet controller problemsThe method that you use to test the Ethernet controller depends on which operatingsystem you are using. See the operating-system documentation for informationabout Ethernet controllers, and see the Ethernet controller device-driver readme file.Try the following procedures:v Make sure that the correct and current device drivers and firmware, which comewith the server, are installed and that they are at the latest level.Important: Some cluster solutions require specific code levels or coordinatedcode updates. If the device is part of a cluster solution, verify that the latest levelof code is supported for the cluster solution before you update the code.v Make sure that the Ethernet cable is installed correctly.120 IBM System x3630 M3 Type 7377: Problem Determination and Service Guide
