User's Manual

Retainingserialnumbers
Thissectionincludesthefollowingdescriptions:
•Restoringtheserialnumberofthesystemunit
•RetainingtheUUID
•ReadingorwritingtheECAinformation
Restoringtheserialnumberofthesystemunit
Whenthecomputerwasmanufactured,theEEPROMonthesystemboardwasloadedwiththeserial
numbersofthesystemandallmajorcomponents.Thesenumbersneedtoremainthesamethroughout
thelifeofthecomputer.
Ifyoureplacethesystemboard,youmustrestoretheserialnumberofthesystemunittoitsoriginalvalue.
Beforereplacingthesystemboard,savetheoriginalserialnumberbydoingthefollowing:
1.InstalltheLENOVOThinkPadHardwareMaintenanceDisketteVersion1.76orlater,andrestartthe
computer.
2.Fromthemainmenu,select1.SetSystemIdentication.
3.Select2.ReadS/NdatafromEEPROM.
Theserialnumberofeachdeviceinyourcomputerisdisplayed;theserialnumberofthesystemunitis
listedasfollows:
•20:Serialnumber
Writedownthatnumber.
Note:Theserialnumberofthesystemunitisalsowrittenonthelabelattachedtothebottomofthecomputer.
Afteryouhavereplacedthesystemboard,restoretheserialnumberbydoingthefollowing:
1.InstalltheLENOVOThinkPadHardwareMaintenanceDisketteVersion1.76orlaterandrestartthe
computer.
2.Fromthemainmenu,select1.SetSystemIdentication.
3.Select1.AddS/NdatafromEEPROM.Followtheinstructionsonthescreen.
IftheMTMandProductIDnumbersdifferfromeachotherontherearlabel,usewhatisshownforthe
ProductIDeld.Seeexamplebelow:
MTMonrearlabel:
TTTT-CTOS/NSSSSSSS
ProductIDonrearlabel:
TTTT-MMM(UsethisnumberwhensettingSerialNumber)
Intheexample,theSerialNumbertobeinputis'1STTTTMMMSSSSSSS'.
RetainingtheUUID
TheUniversallyUniqueIdentier(UUID)isa128-bitnumberuniquelyassignedtoyourcomputerat
productionandstoredintheEEPROMofyoursystemboard.
ThealgorithmthatgeneratesthenumberisdesignedtoprovideuniqueIDsuntiltheyearA.D.3400.Notwo
computersintheworldhavethesamenumber.
56ThinkPadT520,T520i,andW520HardwareMaintenanceManual