HardwareMaintenanceManual
ThinkPadL420,L421,andL520
Note
Beforeusingthisinformationandtheproductitsupports,besuretoreadthegeneralinformationunder
AppendixA“Notices”onpage165
.
SecondEdition(April2011)
©CopyrightLenovo2011.
LIMITEDANDRESTRICTEDRIGHTSNOTICE:IfdataorsoftwareisdeliveredpursuantaGeneralServicesAdministration
“GSA”contract,use,reproduction,ordisclosureissubjecttorestrictionssetforthinContractNo.GS-35F-05925.
Contents
Aboutthismanual...........iii
Chapter1.Safetyinformation.....1
Generalsafety................1
Electricalsafety...............2
Safetyinspectionguide............3
Handlingdevicesthataresensitivetoelectrostatic
discharge..................3
Groundingrequirements............4
Safetynotices(multilingualtranslations)......4
Lasercompliancestatement(multilingual
translations)................18
Chapter2.Importantservice
information..............25
StrategyforreplacingFRUs.........25
Strategyforreplacingaharddiskdrive...26
Importantnoticeforreplacingasystem
board................26
Howtouseerrormessage........26
StrategyforreplacingFRUsforCTO,CMV ,and
GAV...................26
Productdenition............26
FRUidenticationforCTO,CMV ,andGAV
products...............27
Powermanagement............40
Screenblankmode...........40
Sleep(standby)mode..........40
Hibernationmode...........41
Symptom-to-FRUindex...........41
Numericerrorcodes..........42
Errormessages............44
No-beepsymptoms...........44
LCD-relatedsymptoms.........44
Intermittentproblems..........45
Undeterminedproblems.........45
Chapter5.Statusindicators.....47
Chapter6.Fnkeycombinations...49
Chapter7.FRUreplacement
notices................53
Screwnotices...............53
Retainingserialnumbers...........54
Restoringtheserialnumberofthesystem
unit.................54
RetainingtheUUID...........54
ReadingorwritingtheECAinformation...55
Chapter3.Generalcheckout.....29
Whattodorst..............29
Checkoutguide..............30
DiagnosticsusingPC-DoctorforDOS....30
LenovoThinkVantageT oolbox.......33
FRUtests...............33
Powersystemcheckout...........34
Checkingtheacpoweradapter......34
Checkingoperationalcharging......35
Checkingthebatterypack........35
Checkingthebackupbattery.......36
Chapter4.Relatedservice
information..............37
RestoringthefactorycontentsbyusingRecovery
DiscSet.................37
Passwords................38
Power-onpassword...........38
Hard-diskpassword...........38
Supervisorpassword..........39
Howtoremovethepower-onpassword...39
Howtoremovethehard-diskpassword...39
Chapter8.Removingandreplacinga
FRU..................57
1010Batterypack.............57
1020ExpressCardblankbezelandMediaCard
blankbezel................58
1030Opticaldriveortravelcover.......60
1040Thermalcover.............61
1050Harddiskdriveorsolidstatedrive
assembly.................62
1060DIMM................65
1070Fanassembly.............66
1080CPU................68
1090SIMslotcover............69
1110WirelessWANslotcoverandPCIExpress
MiniCardforwirelessWAN..........71
1110mSATAsolidstatedrive.........73
1120Palmrestassemblywithcables......74
1130PCIExpressMiniCardforwirelessLAN..78
1140Backupbattery............80
1150Bluetoothdaughtercard........80
1160MediaCardReaderslotboardandMedia
CardReadercableassembly.........81
1170Keyboard..............83
©CopyrightLenovo2011
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1180Keyboardbezel............85
1190LCDunit...............87
2010T opshieldingassembly.........90
2020Systemboardassembly.........93
2030USBconnectorboardandUSBcable
assembly.................98
2040DC-incableandbasecover.......100
2050LCDfrontbezel............103
2060Speakerassembly...........104
2070Integratedcamera...........105
2080Antennaassembly...........106
2090Hinges,LCDpanel,LCDcable,andLCDrear
coverassembly..............108
Chapter9.Locations........113
Frontview................113
Rearview.................114
Bottomview...............114
Keyboard.................152
Miscellaneousparts............153
acpoweradapters.............154
Powercords...............155
Recoverydiscs..............156
WindowsXPProfessional(32bit)DVDs...156
WindowsVistaHomeBasic(32bit)DVDs..157
WindowsVistaBusiness(32bit)DVDs...157
Windows7HomeBasic(32bit)DVDs....158
Windows7HomePremium(32bit)DVDs..158
Windows7HomePremium(64bit)DVDs..159
Windows7Professional(32bit)DVDs....160
Windows7Professional(64bit)DVDs....160
Windows7Ultimate(32bit)DVDs.....162
Windows7Ultimate(64bit)DVDs.....162
Windows7Starter(32bit)DVDs......162
Commonservicetools...........163
Chapter10.Partslist........115
Overall..................116
LCDFRUs................144
AppendixA.Notices........165
Electronicemissionsnotices.........166
Trademarks................166
iiHardwareMaintenanceManual
Aboutthismanual
ThismanualcontainsserviceandreferenceinformationforthefollowingThinkPad
ThinkPadL420
MachineType(MT)7826,7827,7829,7853,7854,and7856
ThinkPadL421
MT7826,7827,7829,7853,7854,and7856
ThinkPadL520
MT5015,5016,5017,5019,7859,and7860
®
Notebookproducts.
Usethismanualalongwiththeadvanceddiagnosticteststotroubleshootproblems.
Important:
ThismanualisintendedonlyfortrainedservicetechnicianswhoarefamiliarwithThinkPadproducts.Use
thismanualalongwiththeadvanceddiagnosticteststotroubleshootproblemseffectively.
BeforeservicingaThinkPadproduct,besuretoreadalltheinformationunderChapter1“Safety
information”onpage1
andChapter2“Importantserviceinformation”onpage25.
©CopyrightLenovo2011
iii
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Chapter1.Safetyinformation
Thischapterpresentsfollowingsafetyinformationthatyouneedtobefamiliarwithbeforeyouservice
aThinkPadNotebook.
•“Generalsafety”onpage1
•“Electricalsafety”onpage2
•“Safetyinspectionguide”onpage3
•“Handlingdevicesthataresensitivetoelectrostaticdischarge”onpage3
•“Groundingrequirements”onpage4
•“Safetynotices(multilingualtranslations)”onpage4
•“Lasercompliancestatement(multilingualtranslations)”onpage18
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.
•Inserttheendsofyournecktieorscarfinsideclothingorfastenitwithanonconductiveclip,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.
©CopyrightLenovo2011
1
Electricalsafety
Observethefollowingruleswhenworkingonelectricalequipment.
Important:
Useonlyapprovedtoolsandtestequipment.Somehandtoolshavehandlescoveredwithasoftmaterial
thatdoesnotinsulateyouwhenworkingwithliveelectricalcurrents.
Manycustomershave,neartheirequipment,rubberoormatsthatcontainsmallconductivebersto
decreaseelectrostaticdischarges.Donotusethistypeofmattoprotectyourselffromelectricalshock.
•Findtheroomemergencypower-off(EPO)switch,disconnectingswitch,orelectricaloutlet.Ifanelectrical
accidentoccurs,youcanthenoperatetheswitchorunplugthepowercordquickly.
•Donotworkaloneunderhazardousconditionsornearequipmentthathashazardousvoltages.
•Disconnectallpowerbefore:
–Performingamechanicalinspection
–Workingnearpowersupplies
–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
metaloorstripsandmachineframes.
Observethespecialsafetyprecautionswhenyouworkwithveryhighvoltages;Instructionsforthese
precautionsareinthesafetysectionsofmaintenanceinformation.Useextremecarewhenmeasuring
highvoltages.
•Regularlyinspectandmaintainyourelectricalhandtoolsforsafeoperationalcondition.
•Donotusewornorbrokentoolsandtesters.
•Neverassumethatpowerhasbeendisconnectedfromacircuit.First,checkthatithasbeenpoweredoff.
•Alwayslookcarefullyforpossiblehazardsinyourworkarea.Examplesofthesehazardsaremoistoors,
nongroundedpowerextensioncables,powersurges,andmissingsafetygrounds.
•Donottouchliveelectricalcircuitswiththereectivesurfaceofaplasticdentalmirror.Thesurfaceis
conductive;suchtouchingcancausepersonalinjuryandmachinedamage.
•Donotservicethefollowingpartswiththepoweronwhentheyareremovedfromtheirnormaloperating
placesinamachine:
–Powersupplyunits
–Pumps
–Blowersandfans
–Motorgenerators
–Similarunitstolistedabove
Thispracticeensurescorrectgroundingoftheunits.
•Ifanelectricalaccidentoccurs:
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–Usecaution;donotbecomeavictimyourself.
–Switchoffpower.
–Sendanotherpersontogetmedicalaid.
Safetyinspectionguide
Thepurposeofthisinspectionguideistoassistyouinidentifyingpotentiallyunsafeconditions.Aseach
machinewasdesignedandbuilt,requiredsafetyitemswereinstalledtoprotectusersandservicetechnicians
frominjury.Thisguideaddressesonlythoseitems.Y oushouldusegoodjudgmenttoidentifypotential
safetyhazardsduetoattachmentofnon- ThinkPadfeaturesoroptionsnotcoveredbythisinspectionguide.
Ifanyunsafeconditionsarepresent,youmustdeterminehowserioustheapparenthazardcouldbeand
whetheryoucancontinuewithoutrstcorrectingtheproblem.
Considertheseconditionsandthesafetyhazardstheypresent:
•Electricalhazards,especiallyprimarypower(primaryvoltageontheframecancauseseriousorfatal
electricalshock)
•Explosivehazards,suchasadamagedCRTfaceorabulgingcapacitor
•Mechanicalhazards,suchaslooseormissinghardware
Todeterminewhetherthereareanypotentiallyunsafeconditions,usethefollowingchecklistatthebeginning
ofeveryservicetask.Beginthecheckswiththepoweroff,andthepowercorddisconnected.
Checklist:
1.Checkexteriorcoversfordamage(loose,broken,orsharpedges).
2.Poweroffthecomputer.Disconnectthepowercord.
3.Checkthepowercordfor:
a.Athird-wiregroundconnectoringoodcondition.Useametertomeasurethird-wireground
continuityfor0.1ohmorlessbetweentheexternalgroundpinandtheframeground.
b.Thepowercordshouldbethetypespeciedinthepartslist.
c.Insulationmustnotbefrayedorworn.
4.Checkforcrackedorbulgingbatteries.
5.Removethecover.
6.Checkforanyobviousnon-ThinkPadalterations.Usegoodjudgmentastothesafetyofany
non-ThinkPadalterations.
7.Checkinsidetheunitforanyobviousunsafeconditions,suchasmetallings,contamination,wateror
otherliquids,orsignsofreorsmokedamage.
8.Checkforworn,frayed,orpinchedcables.
9.Checkthatthepower-supplycoverfasteners(screwsorrivets)havenotbeenremovedortamperedwith.
Handlingdevicesthataresensitivetoelectrostaticdischarge
Anycomputerpartcontainingtransistorsorintegratedcircuits(ICs)shouldbeconsideredsensitiveto
electrostaticdischarge(ESD.)ESDdamagecanoccurwhenthereisadifferenceinchargebetweenobjects.
ProtectagainstESDdamagebyequalizingthechargesothatthemachine,thepart,theworkmat,andthe
personhandlingthepartareallatthesamecharge.
Notes:
1.Useproduct-specicESDprocedureswhentheyexceedtherequirementsnotedhere.
Chapter1.Safetyinformation3
2.MakesurethattheESDprotectivedevicesyouusehavebeencertied(ISO9000)asfullyeffective.
WhenhandlingESD-sensitiveparts:
•Keepthepartsinprotectivepackagesuntiltheyareinsertedintotheproduct.
•Avoidcontactwithotherpeople.
•Wearagroundedwriststrapagainstyourskintoeliminatestaticonyourbody.
•Preventthepartfromtouchingyourclothing.Mostclothingisinsulativeandretainsachargeevenwhen
youarewearingawriststrap.
•Useagroundedworkmattoprovideastatic-freeworksurface.Thematisespeciallyusefulwhen
handlingESD-sensitivedevices.
•Selectagroundingsystem,suchasthoselistedbelow,toprovideprotectionthatmeetsthespecic
servicerequirement.
Note:TheuseofagroundingsystemtoguardagainstESDdamageisdesirablebutnotnecessary.
–AttachtheESDgroundcliptoanyframeground,groundbraid,orgreen-wireground.
–Whenworkingonadouble-insulatedorbattery-operatedsystem,useanESDcommongroundor
referencepoint.Youcanusecoaxorconnector-outsideshellsonthesesystems.
–Usetheroundgroundprongoftheacplugonac-operatedcomputers.
Groundingrequirements
Electricalgroundingofthecomputerisrequiredforoperatorsafetyandcorrectsystemfunction.Proper
groundingoftheelectricaloutletcanbeveriedbyacertiedelectrician.
Safetynotices(multilingualtranslations)
Thesafetynoticesinthissectionareprovidedinthefollowinglanguages:
•English
•Arabic
•BrazilianPortuguese
•French
•German
•Hebrew
•Japanese
•Korean
•Spanish
•TraditionalChinese
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Lasercompliancestatement(multilingualtranslations)
Thelasercompliancestatementsinthissectionareprovidedinthefollowinglanguages:
•English
•Arabic
•BrazilianPortuguese
•French
•German
•Hebrew
•Japanese
•Korean
•Spanish
•TraditionalChinese
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