Hardware Maintenance Manual

Table5.LCD-relatedsymptoms
Symptomorerror
FRUoraction,insequence
Nobeep,power-onindicatoron,andablankLCDduring
POST.
Replacethesystemboard.
•LCDbacklightnotworking.
•LCDtoodark.
•LCDbrightnesscannotbeadjusted.
•LCDcontrastcannotbeadjusted.
1.ReseattheLCDconnectors.
2.ReplacetheLCDassembly.
3.Replacethesystemboard.
•LCDscreenunreadable.
•Charactersmissingpixels.
•Screenabnormal.
•Wrongcolordisplayed.
1.Seeimportantnotefor“LCD-relatedsymptoms.”
2.ReseatallLCDconnectors.
3.ReplacetheLCDassembly.
4.Replacethesystemboard.
HorizontalorverticallinesdisplayedonLCD.ReplacetheLCDassembly.
Intermittentproblems
Intermittentsystemhangproblemscanbeduetoavarietyofcausesthathavenothingtodowithahardware
defect,suchascosmicradiation,electrostaticdischarge,orsoftwareerrors.FRUreplacementshouldbe
consideredonlywhenaproblemrecurs.
Whenanalyzinganintermittentproblem,dothefollowing:
1.Runthediagnostictestforthesystemboardinloopmodeatleast10times.
2.Ifnoerrorisdetected,donotreplaceanyFRUs.
3.Ifanyerrorisdetected,replacetheFRUshownbytheFRUcode.Rerunthetesttoverifythatno
moreerrorsexist.
Undeterminedproblems
Ifthediagnostictestsdidnotidentifytheadapterordevicethathasfailed,ifwrongdevicesareinstalled,
orifthesystemsimplyisnotoperating,followtheseprocedurestoisolatethefailingFRU(donotisolate
FRUsthathavenodefects).
Verifythatallattacheddevicesaresupportedbythecomputer.
Verifythatthepowersupplybeingusedatthetimeofthefailureisoperatingcorrectly.See“Powersystem
checkout”onpage26.
1.Turnoffthecomputer.
2.VisuallycheckeachFRUfordamage.ReplaceanydamagedFRU.
3.Removeordisconnectallofthefollowingdevices:
a.Non-ThinkPaddevices
b.Devicesattachedtothedockingstationortheportreplicator
c.Printer,mouse,andotherexternaldevices
d.Batterypack
e.Solid-statedrive
f.Externaldiskettedriveoropticaldrive
g.Memorymodule
h.PCcards
4.Turnonthecomputer.
5.Determinewhethertheproblemhasbeensolved.
6.Iftheproblemdoesnotrecur,reconnecttheremoveddevicesoneatatimeuntilyoufindthefailingFRU.
7.Iftheproblemremains,replacethefollowingFRUsoneatatime(donotreplaceanondefectiveFRU):
a.Systemboard
b.LCDassembly
38ThinkPadT460sHardwareMaintenanceManual