Lenovo IdeaCentre B540-B540P Hardware Maintenance Manual

Observethefollowingruleswhenworkingonelectricalequipment.
Important:Useonlyapprovedtoolsandtestequipment.Somehandtoolshavehandlescoveredwithasoft
materialthatdoesnotinsulateyouwhenworkingwithliveelectricalcurrents.Manycustomershave,near
theirequipment,rubberoormatsthatcontainsmallconductiveberstodecreaseelectrostaticdischarges.
Donotusethistypeofmattoprotectyourselffromelectricalshock.
•Findtheroomemergencypower-off(EPO)switch,disconnectingswitch,orelectricaloutlet.Ifanelectrical
accidentoccurs,youcanthenoperatetheswitchorunplugthepowercordquickly.
•Donotworkaloneunderhazardousconditionsornearequipmentthathashazardousvoltages.
•Disconnectallpowerbefore:
–Performingamechanicalinspection
–Workingnearpowersupplies
–RemovingorinstallingFieldReplaceableUnits(FRUs)
•Beforeyoustarttoworkonthemachine,unplugthepowercord.Ifyoucannotunplugit,askthecustomer
topower-offthewallboxthatsuppliespowertothemachineandtolockthewallboxintheoffposition.
•Ifyouneedtoworkonamachinethathasexposedelectricalcircuits,observethefollowingprecautions:
–Ensurethatanotherperson,familiarwiththepower-offcontrols,isnearyou.
Remember:Anotherpersonmustbetheretoswitchoffthepower,ifnecessary.
–Useonlyonehandwhenworkingwithpowered-onelectricalequipment;keeptheotherhandinyour
pocketorbehindyourback.
Remember:Theremustbeacompletecircuittocauseelectricalshock.Byobservingtheaboverule,
youmaypreventacurrentfrompassingthroughyourbody.
–Whenusingatester,setthecontrolscorrectlyandusetheapprovedprobeleadsandaccessoriesfor
thattester.
–Standonsuitablerubbermats(obtainedlocally,ifnecessary)toinsulateyoufromgroundssuchas
metaloorstripsandmachineframes.
Observethespecialsafetyprecautionswhenyouworkwithveryhighvoltages;theseinstructionsarein
thesafetysectionsofmaintenanceinformation.Useextremecarewhenmeasuringhighvoltages.
•Regularlyinspectandmaintainyourelectricalhandtoolsforsafeoperationalcondition.
•Donotusewornorbrokentoolsandtesters.
•Neverassumethatpowerhasbeendisconnectedfromacircuit.First,checkthatithasbeenpowered-off.
•Alwayslookcarefullyforpossiblehazardsinyourworkarea.Examplesofthesehazardsaremoistoors,
nongroundedpowerextensioncables,powersurges,andmissingsafetygrounds.
•Donottouchliveelectricalcircuitswiththereectivesurfaceofaplasticdentalmirror.Thesurfaceis
conductive;suchtouchingcancausepersonalinjuryandmachinedamage.
•Donotservicethefollowingpartswiththepoweronwhentheyareremovedfromtheirnormaloperating
placesinamachine:
–Powersupplyunits
–Pumps
–Blowersandfans
–Motorgenerators
andsimilarunits.(Thispracticeensurescorrectgroundingoftheunits.)
•Ifanelectricalaccidentoccurs:
–Usecaution;donotbecomeavictimyourself.
–Switchoffpower.
4IdeaCentreB540–B540PHardwareMaintenanceManual