Intermittentproblems
Intermittentsystemhangproblemscanbeduetoavarietyofcausesthathavenothingtodowithahardware
defect,suchascosmicradiation,electrostaticdischarge,orsoftwareerrors.FRUreplacementshouldbe
consideredonlywhenaproblemrecurs.
Undeterminedproblems
Ifthediagnostictestsdidnotidentifythedevicethathasfailed,ifwrongdevicesareinstalled,orifthe
systemsimplyisnotoperating,followtheseprocedurestoisolatethefailingFRU(donotisolateFRUs
thathavenodefects).
Verifythatallattacheddevicesaresupportedbythecomputer.
Verifythatthepowersupplybeingusedatthetimeofthefailureisoperatingcorrectly.(See“Powersystem
checkout”onpage30)
1.Turnoffthecomputer.
2.VisuallycheckeachFRUfordamage.ReplaceanydamagedFRU.
3.Removeordisconnectallofthefollowingdevices:
a.Non-ThinkPaddevices
b.Printer,mouse,andotherexternaldevices
c.Batterypack
d.Harddiskdrive
e.Externaldiskettedriveoropticaldrive
f.DIMM
g.Opticaldiskordisketteintheinternaldrive
h.PCCards
4.Turnonthecomputer.
5.Determinewhethertheproblemhasbeensolved.
6.Iftheproblemdoesnotrecur,reconnecttheremoveddevicesoneatatimeuntilyoundthefailingFRU.
7.Iftheproblemremains,replacethefollowingFRUsoneatatime(donotreplaceanondefectiveFRU):
a.Systemboard
b.LCDassembly
42HardwareMaintenanceManual