Table6.LCD-relatedsymptoms(continued)
Symptomorerror
FRUoraction,insequence
•LCDscreenunreadable.
•Charactersmissingpixels.
•Screenabnormal.
•Wrongcolordisplayed.
1.Seeimportantnotefor“LCD-relatedsymptoms.”
2.ReseatallLCDconnectors.
3.LCDassembly.
4.Systemboard.
HorizontalorverticallinesdisplayedonLCD.LCDassembly.
Intermittentproblems
Intermittentsystemhangproblemscanbeduetoavarietyofcausesthathavenothingtodowithahardware
defect,suchascosmicradiation,ESD,orsoftwareerrors.FRUreplacementshouldbeconsideredonly
whenaproblemrecurs.
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
Chapter4.Relatedserviceinformation43