
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,electrostaticdischarge,orsoftwareerrors.FRUreplacementshouldbe
consideredonlywhenaproblemrecurs.
Whenanalyzinganintermittentproblem,dothefollowing:
1.Runthediagnostictestforthesystemboardinloopmodeatleast10times.
2.Foreachtest,dooneofthefollowing:
•Ifnoerrorisdetected,donotreplaceanyFRUs.
•Ifanyerrorisdetected,replacetheFRUshownbytheFRUcode.Rerunthetesttoverifythat
nomoreerrorsexist.
Undeterminedproblems
Ifthediagnostictestsdidnotidentifytheadapterordevicethathasfailed,ifwrongdevicesareinstalled,
orifthesystemsimplyisnotoperating,followtheseprocedurestoisolatethefailingFRU(donotisolate
FRUsthathavenodefects).
Verifythatallattacheddevicesaresupportedbythecomputer.
Verifythatthepowersupplybeingusedatthetimeofthefailureisoperatingcorrectly.(See“Powersystem
checkout”onpage24
.)
1.Turnoffthecomputer.
2.VisuallycheckeachFRUfordamage.ReplaceanydamagedFRU.
3.Removeordisconnectallofthefollowingdevices:
a.Non-ThinkPaddevices
b.Devicesattachedtothedockingstationortheportreplicator
c.Printer,mouse,andotherexternaldevices
d.Batterypack
e.Harddiskdrive
f.Externaldiskettedriveoropticaldrive
g.Memorymodule
h.PCCards
4.Turnonthecomputer.
5.Determinewhethertheproblemhasbeensolved.
6.Iftheproblemdoesnotrecur,reconnecttheremoveddevicesoneatatimeuntilyoundthefailingFRU.
7.Iftheproblemremains,replacethefollowingFRUsoneatatime(donotreplaceanondefectiveFRU):
a.Systemboard
b.LCDassembly
Chapter4.Relatedserviceinformation41
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