Computer Hardware User Manual

Solvingpowerproblems
Powerproblemscanbedifculttosolve.Forexample,ashortcircuitcanexistanywhereonanyofthe
powerdistributionbuses.Usually,ashortcircuitwillcausethepowersubsystemtoshutdownbecauseof
anovercurrentcondition.Todiagnoseapowerproblem,usethefollowinggeneralprocedure:
Step1.Turnofftheserveranddisconnectallacpowercords.
Step2.Checkthepower-faultLEDsonthesystemboard(see“Powerproblems”onpage58).
Step3.Checkforloosecablesinthepowersubsystem.Alsocheckforshortcircuits,forexample,ifa
loosescrewiscausingashortcircuitonacircuitboard.
Step4.Removetheadaptersanddisconnectthecablesandpowercordstoallinternalandexternal
devicesuntiltheserverisattheminimumcongurationthatisrequiredfortheservertostart(see
“Solvingundeterminedproblems”onpage104
fortheminimumconguration).
Step5.Reconnectallacpowercordsandturnontheserver.Iftheserverstartssuccessfully,reseatthe
adaptersanddevicesoneatatimeuntiltheproblemisisolated.
Iftheserverdoesnotstartfromtheminimumconguration,see“Power-supplyLEDs”onpage63toreplace
thecomponentsintheminimumcongurationoneatatimeuntiltheproblemisisolated.
SolvingEthernetcontrollerproblems
ThemethodthatyouusetotesttheEthernetcontrollerdependsonwhichoperatingsystemyouareusing.
Seetheoperating-systemdocumentationforinformationaboutEthernetcontrollers,andseetheEthernet
controllerdevice-driverreadmele.
Trythefollowingprocedures:
•Makesurethatthecorrectdevicedrivers,whichcomewiththeserverareinstalledandthattheyareat
thelatestlevel.
•MakesurethattheEthernetcableisinstalledcorrectly.
–Thecablemustbesecurelyattachedatallconnections.Ifthecableisattachedbuttheproblem
remains,tryadifferentcable.
–IfyousettheEthernetcontrollertooperateat100Mbps,youmustuseCategory5cabling.
–Ifyoudirectlyconnecttwoservers(withoutahub),orifyouarenotusingahubwithXports,usea
crossovercable.TodeterminewhetherahubhasanXport,checktheportlabel.Ifthelabelcontains
anX,thehubhasanXport.
•Determinewhetherthehubsupportsauto-negotiation.Ifitdoesnot,tryconguringtheintegrated
Ethernetcontrollermanuallytomatchthespeedandduplexmodeofthehub.
•ChecktheEthernetcontrollerLEDsontherearpaneloftheserver.TheseLEDsindicatewhetherthere
isaproblemwiththeconnector,cable,orhub.
–TheEthernetlinkstatusLEDislitwhentheEthernetcontrollerreceivesalinkpulsefromthehub.Ifthe
LEDisoff,theremightbeadefectiveconnectororcableoraproblemwiththehub.
–TheEthernettransmit/receiveactivityLEDislitwhentheEthernetcontrollersendsorreceivesdata
overtheEthernetnetwork.IftheEthernettransmit/receiveactivityisoff,makesurethatthehuband
networkareoperatingandthatthecorrectdevicedriversareinstalled.
•ChecktheLANactivityLEDontherearoftheserver.TheLANactivityLEDislitwhendataisactiveon
theEthernetnetwork.IftheLANactivityLEDisoff,makesurethatthehubandnetworkareoperating
andthatthecorrectdevicedriversareinstalled.
•Checkforoperating-system-speciccausesoftheproblem.
•Makesurethatthedevicedriversontheclientandserverareusingthesameprotocol.
IftheEthernetcontrollerstillcannotconnecttothenetworkbutthehardwareappearstobeworking,the
networkadministratormustinvestigateotherpossiblecausesoftheerror.
Chapter4.Diagnostics103