Lenovo N20 User Manual

HardwareMaintenanceManual

LenovoN20Chromebook

HardwareMaintenanceManual

LenovoN20Chromebook

FirstEdition(May2014)

©CopyrightLenovo2014.

Contents

Chapter1.Safetyinformation.....1

Generalsafety...............1

Electricalsafety..............1

Safetyinspectionguide...........2

Handlingdevicesthataresensitivetoelectrostatic

discharge.................3

Groundingrequirements...........4

Safetynotices(multilingualtranslations).....4

Chapter2.Generalcheckout.....19

Whattodoﬁrst..............19

Checkingtheacpoweradapter........20

Chapter3.IdetifyingFRUs(CRUs)..21

AllFRUs(CRUs)forLenovoN20Chromebook..21 LenovopartnumbersofreplacementFRUsor

CRUs..................24

Chapter4.RemovingaFRUorCRU.29

Generalguidelines.............29

Removethekeyboard............29

Removetheuppercase...........31

RemovetheWLAN&Bluetoothcombomodule..33

RemovetheLCDmodule..........34

Removethedc-inconnector.........35

Removethebatterypack..........37

Removethespeakers............38

RemovethesystemboardandtheI/Oboard...39

DisassembletheLCDmodule.........40

RemovetheLCDbezel..........40

RemovetheLCDpanel.........41

Removethehinges,theLCDcable,andthe

WLANantennas............42

Removethecameraboardandthecamera

cable.................43

AppendixA.Features,controls,and

connectors..............45

AppendixB.Lenovopartnumbersof screwsusedonN20Chromebook..47

AppendixC.Lenovopartnumbersof

acadaptersandpowercords....49

AppendixD.Labellocations.....51

Trademarks................liii

©CopyrightLenovo2014

iii

ivHardwareMaintenanceManual

Chapter1.Safetyinformation

Thischapterpresentsthefollowingsafetyinformationthatyouneedtobefamiliarwithbeforeyouservicea Lenovonotebookcomputer.

Generalsafety

Followtheserulestoensuregeneralsafety:

•Observegoodhousekeepingintheareaofthemachinesduringandaftermaintenance.

•Whenliftinganyheavyobject:

1.Makesurethatyoucanstandsafelywithoutslipping.

2.Distributetheweightoftheobjectequallybetweenyourfeet.

3.Useaslowliftingforce.Nevermovesuddenlyortwistwhenyouattempttolift.

4.Liftbystandingorbypushingupwithyourlegmuscles;thisactionremovesthestrainfromthe musclesinyourback.Donotattempttoliftanyobjectthatweighsmorethan16kg(35lb)orthat

youthinkistooheavyforyou.

•Donotperformanyactionthatcauseshazardstothecustomer,orthatmakestheequipmentunsafe.

•Beforeyoustartthemachine,makesurethatotherservicetechniciansandthecustomer'spersonnelare notinahazardousposition.

•Placeremovedcoversandotherpartsinasafeplace,awayfromallpersonnel,whileyouareservicing themachine.

•Keepyourtoolcaseawayfromwalkareassothatotherpeoplewillnottripoverit.

•Donotwearlooseclothingthatcanbetrappedinthemovingpartsofamachine.Makesurethatyour sleevesarefastenedorrolledupaboveyourelbows.Ifyourhairislong,fastenit.

•Inserttheendsofyournecktieorscarfinsideclothingorfastenitwithanon-conductiveclip,about8 centimeters(3inches)fromtheend.

•Donotwearjewelry,chains,metal-frameeyeglasses,ormetalfastenersforyourclothing.

Attention:Metalobjectsaregoodelectricalconductors.

•Wearsafetyglasseswhenyouarehammering,drilling,soldering,cuttingwire,attachingsprings,using solvents,orworkinginanyotherconditionsthatmightbehazardoustoyoureyes.

•Afterservice,reinstallallsafetyshields,guards,labels,andgroundwires.Replaceanysafetydevice thatiswornordefective.

•Reinstallallcoverscorrectlybeforereturningthemachinetothecustomer.

•Fanlouversonthemachinehelptopreventoverheatingofinternalcomponents.Donotobstructfan louversorcoverthemwithlabelsorstickers.

Electricalsafety

Observethefollowingruleswhenworkingonelectricalequipment.

Important:Useonlyapprovedtoolsandtestequipment.Somehandtoolshavehandlescoveredwithasoft materialthatdoesnotinsulateyouwhenworkingwithliveelectricalcurrents.Manycustomershave,near theirequipment,rubberﬂoormatsthatcontainsmallconductiveﬁberstodecreaseelectrostaticdischarges. Donotusethistypeofmattoprotectyourselffromelectricalshock.

•Findtheroomemergencypower-off(EPO)switch,disconnectingswitch,orelectricaloutlet.Ifanelectrical accidentoccurs,youcanthenoperatetheswitchorunplugthepowercordquickly.

•Donotworkaloneunderhazardousconditionsornearequipmentthathashazardousvoltages.

•Disconnectallpowerbefore: –Performingamechanicalinspection –Workingnearpowersupplies

©CopyrightLenovo2014

–Removingorinstallingmainunits

•Beforeyoustarttoworkonthemachine,unplugthepowercord.Ifyoucannotunplugit,askthecustomer topower-offthewallboxthatsuppliespowertothemachine,andtolockthewallboxintheoffposition.

•Ifyouneedtoworkonamachinethathasexposedelectricalcircuits,observethefollowingprecautions: –Ensurethatanotherperson,familiarwiththepower-offcontrols,isnearyou.

Attention:Anotherpersonmustbetheretoswitchoffthepower,ifnecessary.

–Useonlyonehandwhenworkingwithpowered-onelectricalequipment;keeptheotherhandinyour

pocketorbehindyourback.

Attention:Anelectricalshockcanoccuronlywhenthereisacompletecircuit.Byobservingtheabove rule,youmaypreventacurrentfrompassingthroughyourbody.

–Whenusingtesters,setthecontrolscorrectlyandusetheapprovedprobeleadsandaccessoriesfor

thattester.

–Standonsuitablerubbermats(obtainedlocally,ifnecessary)toinsulateyoufromgroundssuchas

metalﬂoorstripsandmachineframes. Observethespecialsafetyprecautionswhenyouworkwithveryhighvoltages;Instructionsforthese precautionsareinthesafetysectionsofmaintenanceinformation.Useextremecarewhenmeasuring highvoltages.

•Regularlyinspectandmaintainyourelectricalhandtoolsforsafeoperationalcondition.

•Donotusewornorbrokentoolsandtesters.

•Neverassumethatpowerhasbeendisconnectedfromacircuit.First,checkthatithasbeenpoweredoff.

•Alwayslookcarefullyforpossiblehazardsinyourworkarea.Examplesofthesehazardsaremoistﬂoors, non-groundedpowerextensioncables,powersurges,andmissingsafetygrounds.

•Donottouchliveelectricalcircuitswiththereﬂectivesurfaceofaplasticdentalmirror.Thesurfaceis conductive;suchtouchingcancausepersonalinjuryandmachinedamage.

•Donotservicethefollowingpartswiththepoweronwhentheyareremovedfromtheirnormaloperating placesinamachine: –Powersupplyunits –Pumps –Blowersandfans –Motorgenerators –Similarunitsaslistedabove Thispracticeensurescorrectgroundingoftheunits.

•Ifanelectricalaccidentoccurs: –Usecaution;donotbecomeavictimyourself. –Switchoffpower. –Sendanotherpersontogetmedicalaid.

Safetyinspectionguide

Thepurposeofthisinspectionguideistoassistyouinidentifyingpotentiallyunsafeconditions.Aseach machinewasdesignedandbuilt,requiredsafetyitemswereinstalledtoprotectusersandservicetechnicians frominjury.Thisguideaddressesonlythoseitems.Youshouldusegoodjudgmenttoidentifypotential safetyhazardsduetoattachmentofnon-Lenovofeaturesoroptionsnotcoveredbythisinspectionguide.

Ifanyunsafeconditionsarepresent,youmustdeterminehowserioustheapparenthazardcouldbeand whetheryoucancontinuewithoutﬁrstcorrectingtheproblem.

Considertheseconditionsandthesafetyhazardstheypresent:

•Electricalhazards,especiallyprimarypower(primaryvoltageontheframecancauseseriousorfatal electricalshock)

•Explosivehazards,suchasadamagedcathoderaytube(CRT)faceorabulgingcapacitor

•Mechanicalhazards,suchaslooseormissinghardware

2HardwareMaintenanceManual

Todeterminewhetherthereareanypotentiallyunsafeconditions,usethefollowingchecklistatthebeginning ofeveryservicetask.Beginthecheckswiththepoweroff,andthepowercorddisconnected.

Checklist:

1.Checkexteriorcoversfordamage(loose,broken,orsharpedges).

2.Poweroffthecomputer.Disconnectthepowercord.

3.Checkthepowercordfor:

a.Athird-wiregroundconnectoringoodcondition.Useametertomeasurethird-wireground

continuityfor0.1ohmorlessbetweentheexternalgroundpinandtheframeground.

b.Thepowercordshouldbetheauthorizedtypespeciﬁedforyourcomputer.Goto:

http://www.lenovo.com/serviceparts-lookup

c.Insulationmustnotbefrayedorworn.

4.Checkforcrackedorbulgingbatteries.

5.Removethecover.

6.Checkforanyobviousnon-Lenovoalterations.Usegoodjudgmentastothesafetyofanynon-Lenovo alterations.

7.Checkinsidetheunitforanyobviousunsafeconditions,suchasmetalﬁlings,contamination,wateror otherliquids,orsignsofﬁreorsmokedamage.

8.Checkforworn,frayed,orpinchedcables.

9.Checkthatthepower-supplycoverfasteners(screwsorrivets)havenotbeenremovedortamperedwith.

Handlingdevicesthataresensitivetoelectrostaticdischarge

Anycomputerpartcontainingtransistorsorintegratedcircuits(ICs)shouldbeconsideredsensitiveto electrostaticdischarge(ESD).ESDdamagecanoccurwhenthereisadifferenceinchargebetweenobjects. ProtectagainstESDdamagebyequalizingthechargesothatthemachine,thepart,theworkmat,andthe personhandlingthepartareallatthesamecharge.

Notes:

1.Useproduct-speciﬁcESDprocedureswhentheyexceedtherequirementsnotedhere.

2.MakesurethattheESDprotectivedevicesyouusehavebeencertiﬁed(ISO9000)asfullyeffective.

WhenhandlingESD-sensitiveparts:

•Keepthepartsinprotectivepackagesuntiltheyareinsertedintotheproduct.

•Avoidcontactwithotherpeople.

•Wearagroundedwriststrapagainstyourskintoeliminatestaticonyourbody.

•Preventthepartfromtouchingyourclothing.Mostclothingisinsulativeandretainsachargeeven whenyouarewearingawriststrap.

•Useagroundedworkmattoprovideastatic-freeworksurface.Thematisespeciallyusefulwhen handlingESD-sensitivedevices.

•Selectagroundingsystem,suchasthoselistedbelow,toprovideprotectionthatmeetsthespeciﬁc servicerequirement.

Note:TheuseofagroundingsystemtoguardagainstESDdamageisdesirablebutnotnecessary. –AttachtheESDgroundcliptoanyframeground,groundbraid,orgreen-wireground. –Whenworkingonadouble-insulatedorbattery-operatedsystem,useanESDcommongroundor

referencepoint.Youcanusecoaxorconnector-outsideshellsonthesesystems.

–Usetheroundgroundprongoftheacplugonac-operatedcomputers.

Chapter1.Safetyinformation3

Groundingrequirements

Electricalgroundingofthecomputerisrequiredforoperatorsafetyandcorrectsystemfunction.Proper groundingoftheelectricaloutletcanbeveriﬁedbyacertiﬁedelectrician.