•Itisrecommendedtouseeachscrewonlyonce.
Tightenscrewsasfollows:
•Plastictoplastic
Turnanadditional90degreesafterthescrewheadtouchesthesurfaceoftheplasticpart.
90degreesmore
(Cross-section)
•Logiccardtoplastic
Turnanadditional180degreesafterthescrewheadtouchesthesurfaceofthelogiccard.
180degreesmore
(Cross-section)
Notes:
•Ensurethatyouusethecorrectscrew.Itisrecommendedtousenewscrewsforreplacements.Ifyou
haveatorquescrewdriver,tightenallscrewsfirmlytothetorquespecifiedinthescrewinformation
tableforeachstep.
•Ensurethattorquescrewdriversarecalibratedcorrectlyfollowingcountryspecifications.
Retainingserialnumbers
Thissectionincludesthefollowingdescriptions:
•“Restoringtheserialnumberofthesystemunit”onpage56
•“RetainingtheUUID”onpage57
•“ReadingorwritingtheECAinformation”onpage58
Restoringtheserialnumberofthesystemunit
Whenthecomputerwasmanufactured,theEEPROMonthesystemboardwasloadedwiththeserial
numbersofthesystemandallmajorcomponents.Thesenumbersneedtoremainthesamethroughout
thelifeofthecomputer.
Ifyoureplacethesystemboard,youmustrestoretheserialnumberofthesystemunittoitsoriginalvalue.
Theserialnumberofthesystemunitiswrittenonthelabelattachedtothebottomofthecomputer.
Ifyoucannotfindtheserialnumberofthesystemunitonthebottomofthecomputer,trythefollowing
methodtogetthenumber:
Note:Beforeyouperformtheoperation,ensurethattheUEFI/LegacysettingwithintheStartupmenuin
theThinkPadSetupprogramissettoUEFIOnly.
1.ConnectaUSBmemorykeytothecomputer.
5611e4thGenandY oga11e4thGenHardwareMaintenanceManual