Observethefollowingruleswhenworkingonelectricalequipment.
Important:Useonlyapprovedtoolsandtestequipment.Somehandtoolshavehandlescoveredwithasoft
materialthatdoesnotinsulateyouwhenworkingwithliveelectricalcurrents.Manycustomershaverubber
floormatsneartheirequipmentthatcontainsmallconductivefiberstodecreaseelectrostaticdischarge.
•Findtheroomemergencypower-off(EPO)switch,disconnectingswitch,orelectricaloutlet.Ifanelectrical
accidentoccurs,youcanthenoperatetheswitchorunplugthepowercordquickly.
•Donotworkaloneunderhazardousconditionsornearequipmentthathashazardousvoltages.
•Disconnectallpowerbefore:
–Performingamechanicalinspection
–Workingnearpowersupplies
–RemovingorinstallingFieldReplaceableUnits(FRUs)
•Beforeyoustarttoworkonthecomputer,unplugthepowercord.Ifyoucannotunplugit,askthe
customertopower-offtheelectricaloutletthatsuppliespowertothemachineandtolocktheelectrical
outletintheoffposition.
•Ifyouneedtoworkonacomputerthathasexposedelectricalcircuits,observethefollowingprecautions:
–Ensurethatanotherperson,familiarwiththepower-offcontrols,isnearyou.
Remember:Anotherpersonmustbetheretoswitchoffthepower,ifnecessary.
–Useonlyonehandwhenworkingwithpowered-onelectricalequipment;keeptheotherhandinyour
pocketorbehindyourback.
Remember:Theremustbeacompletecircuittocauseelectricalshock.Byobservingtheaboverule,
youmaypreventacurrentfrompassingthroughyourbody.
–Whenusingatester,setthecontrolscorrectlyandusetheapprovedprobeleadsandaccessoriesfor
thattester.
–Standonsuitablerubbermats(obtainedlocally,ifnecessary)toinsulateyoufromgroundssuchas
metalfloorstripsandmachineframes.
Observethespecialsafetyprecautionswhenyouworkwithveryhighvoltages;theseinstructionsarein
thesafetysectionsofthemaintenanceinformation.Useextremecarewhenmeasuringhighvoltages.
•Regularlyinspectandmaintainyourelectricalhandtoolstoensuretheyaresafetouse.
•Donotusewornorbrokentoolsandtesters.
•Neverassumethatpowerhasbeendisconnectedfromacircuit.First,checkthatithasbeenpoweredoff.
•Alwayslookcarefullyforpossiblehazardsinyourworkarea.Examplesofthesehazardsarewetfloors,
non-groundedpowerextensioncables,conditionsthatmaycauseorallowpowersurges,andmissing
safetygrounds.
•Donottouchliveelectricalcircuitswiththereflectivesurfaceofaplasticdentalmirror.Thissurfaceis
conductive,andtouchingalivecircuitcancausepersonalinjuryanddamagetothecomputer.
•Donotservicethefollowingpartswiththepoweronwhentheyareremovedfromtheirnormaloperating
positionsinacomputer:
–Powersupplyunits
–Pumps
–Blowersandfans
–Motorgenerators
andsimilarunits.(Thispracticeensurescorrectgroundingoftheunits.)
•Ifanelectricalaccidentoccurs:
–Usecaution;donotbecomeavictimyourself.
4IdeaCentreHorizon227All-In-OnePCHardwareMaintenanceManual
