The following table describes the problems that are indicated by variouscombinations of the power-supply LEDs on a dc power supply and suggestedactions to correct the detected problems.DC power-supply LEDsDescription Action NotesIN OK OUT OK Error (!)On On Off Normal operationOff Off Off No dc power to theserver or a problemwith the dc powersource.1. Check the dc power to theserver.2. Make sure that the powercord is connected to afunctioning power source.3. Restart the server. If the errorremains, check thepower-supply LEDs.4. Replace the power-supply.This is a normalcondition when no dcpower is present.Off Off On No dc power to theserver or a problemwith the dc powersource and thepower-supply haddetected an internalproblem.v Make sure that the power cordis connected to a functioningpower source.v Replace the power supply(see the documentation thatcomes with the power supplyfor instructions).Off On Off Faultypower-supplyReplace the power supply.Off On On Faultypower-supplyReplace the power supply.On Off Off Power-supply notfully seated, faultysystem board, orfaulty power-supply1. Reseat the power supply.2. If a power channel error LEDon the system board is not lit,replace the power-supply(see the documentation thatcomes with the power supplyfor instructions).3. If a power channel error LEDon the system board is lit,(trained service technicianonly) replace the systemboard.Typically indicates apower-supply is notfully seated.On Off On Faultypower-supplyReplace the power supply.On On On Power-supply isfaulty but stilloperationalReplace the power supply.System pulse LEDsThe following LEDs are on the system board and monitors the system power-onand power-off sequencing and boot progress (see “System-board LEDs” on page45 for the location of these LEDs):Chapter 1. The System x3550 M2 server 31
