Hardware Maintenance Manual

Intermittentproblems
Intermittentsystemhangproblemscanbeduetoavarietyofcausesthathavenothingtodowithahardware
defect,suchascosmicradiation,electrostaticdischarge,orsoftwareerrors.FRUreplacementshouldbe
consideredonlywhenaproblemrecurs.
Undeterminedproblems
Ifthediagnostictestsdidnotidentifythedevicethathasfailed,ifwrongdevicesareinstalled,orifthe
systemsimplyisnotoperating,followtheseprocedurestoisolatethefailingFRU(donotisolateFRUs
thathavenodefects).
Verifythatallattacheddevicesaresupportedbythecomputer.
Verifythatthepowersupplybeingusedatthetimeofthefailureisoperatingcorrectly.(See“Powersystem
checkout”onpage28
)
1.T urnoffthecomputer.
2.VisuallycheckeachFRUfordamage.ReplaceanydamagedFRU.
3.Removeordisconnectallofthefollowingdevices:
a.Non-ThinkPaddevices
b.Printer,mouse,andotherexternaldevices
c.Harddiskdriveorsolid-statedrive
d.Externaldiskettedriveoropticaldrive
e.Mediacard
4.T urnonthecomputer.
5.Determinewhethertheproblemhasbeensolved.
6.Iftheproblemdoesnotrecur,reconnecttheremoveddevicesoneatatimeuntilyoufindthefailingFRU.
7.Iftheproblemremains,replacethefollowingFRUsoneatatime(donotreplaceanondefectiveFRU):
a.Systemboard
b.LCDassembly
Chapter4.Relatedserviceinformation41