In multi-node configurations, you can also press this button during startup to startthe server as a stand-alone server.Light path diagnostics LEDsThis topic provides a table that describes the LEDs on the light path diagnosticspanel.The following table describes the LEDs on the light path diagnostics panel. If theinformation LED or system-error LED on the front of the server is lit, determinewhether any LEDs on the light path diagnostics panel are lit, and then refer to thistable for the suggested action to correct the detected problem.v Follow the suggested actions in the order in which they are listed in the Action column until the problem issolved.v See Chapter 4, “Parts listing, Types 7145, 7146, 7143, and 7191,” on page 81 to determine which components arecustomer replaceable units (CRU) and which components are field replaceable units (FRU).v If an action step is preceded by “(Trained service technician only),” that step must be performed only by atrained service technician.Light pathdiagnostics LED Description ActionAll LEDs are off (onlythe power LED is litor flashing).No action is necessary.All LEDs are off (thepower LED is lit orflashing and thesystem-error LED islit).A machine check has occurred. Theserver is identifying the machinecheck, the server was interruptedwhile identifying the machinecheck, or the server was unable toidentify the machine check.1. Wait several minutes for the server to identify themachine check, and the server will restart.2. (Trained service technician only) Extract themachine check data, which will be used to identifythe machine check.OVERSPEC There is insufficient power topower the system. The LOG LEDmight also be lit.1. Add a power supply if only one power supply isinstalled.2. Use 220 V ac instead of 110 V ac.3. Reseat the power supply (see “Removing ahot-swap power supply” on page 123 and“Replacing the hot-swap power supply” on page127).4. Remove optional devices.5. Replace the power supply.LOG Information is present in thesystem-event log. 1. Check the log for possible errors.2. Save the log if necessary and clear it.Chapter 3. Diagnostics 63
