Table 22. Microprocessor and memory expansion tray LEDsLEDs DescriptionLight path power LED When this LED is lit, it indicates that thecapacitor on the microprocessor andmemory expansion tray has sufficient powerto light the error LEDs.Microprocessor and memory expansion trayboard error LEDWhen this LED is lit, it indicates that themicroprocessor and memory expansion trayboard has failed.System board error LED When this LED is lit, it indicates that anerror has occurred on the base system board.Light path diagnostics LEDsThis information provides descriptions for the light path diagnostics LEDs.The following table describes the LEDs on the light path diagnostics panel andsuggested actions to correct the detected problems. For additional information, see“Server controls, LEDs, and power” on page 17 and the “System-board LEDs” onpage 33 for the location of the system board LEDs.Note: Check the IMM event log or the system-event log for additional informationbefore you replace a FRU.Table 23. Light path diagnostics panel LEDsv Follow the suggested actions in the order in which they are listed in the Action column until the problem issolved.v See Chapter 3, "Parts listing", to determine which components are customer replaceable units (CRU) andwhich components are field replaceable units (FRU).v If a action step is preceded by (Trained service technician only), that step must be performed only by a trainedservice technician.LED Description ActionNone, but thesystem errorLED is lit.An error has occurred andcannot be isolated. The erroris not represented by a path.Use the Setup utility to check the system event log for informationabout the error (see “Using the Setup utility” on page 142).PS A power supply has failed. 1. Check the power-supply in the server that has an lit amber LED(see “Power-supply LEDs” on page 179).2. Make sure that the power supplies are seated correctly.3. Remove one of the power supplies to isolate the failed powersupply.4. Replace the failed power supply.OVER SPEC The server is using morepower than the powersupplies can output.1. Install an additional power supply or change the input powersource from 110 V to 220 V.2. Remove any recently installed options.3. Restart the server to see whether the problem remains.174 System x3750 M4 Types 8722 and 8733: Installation and Service Guide
