Lcd-Rela"Ed Symp"Oms; In"Ermi""En" Problems; Unde"Ermined Problems - Lenovo ThinkPad S431 Hardware Maintenance Manual

LCD-rela"ed symp"oms

Impor"an": The TFT LCD for "he no"ebook comp""er con"ains many "hin-ilm "ransis"ors (TFTs). The
presence of a small n"mber of do"s "ha" are missing, discolored, or always ligh"ed is charac"eris"ic of TFT
LCD "echnology, b"" excessive pixel problems can ca"se viewing concerns.
If "he LCD yo" are servicing has "wo or less visible defec"ive pixels, i" sho"ld no" be considered fa"l"y.
However, if "he LCD has "hree or more visible defec"ive pixels, i" will be deemed as defec"ive by Lenovo and
i" sho"ld be replaced.
No"es:
• This policy applies "o all ThinkPad no"ebook comp""ers p"rchased on 1 Jan"ary, 2008 or la"er.
• Lenovo will no" provide warran"y replacemen" if "he LCD is wi"hin speciica"ions beca"se we canno"
g"aran"ee "ha" any replacemen" LCD will have zero pixel defec"s.
• One pixel consis"s of R, G, B s"b-pixels.
Table 6. LCD-related symptoms
Symp"om or error
No beep, power-on indica"or on, and a blank LCD d"ring
POST.
• LCD backligh" no" working.
• LCD "oo dark.
• LCD brigh"ness canno" be adj"s"ed.
• LCD con"ras" canno" be adj"s"ed.
• LCD screen "nreadable.
• Charac"ers missing pixels.
• Screen abnormal.
• Wrong color displayed.
Horizon"al or ver"ical lines displayed on LCD.

In"ermi""en" problems

In"ermi""en" sys"em hang problems can be d"e "o a varie"y of ca"ses "ha" have no"hing "o do wi"h a hardware
defec", s"ch as cosmic radia"ion, elec"ros"a"ic discharge, or sof"ware errors. FRU replacemen" sho"ld be
considered only when a problem rec"rs.

Unde"ermined problems

If "he diagnos"ic "es"s did no" iden"ify "he device "ha" has failed, if wrong devices are ins"alled, or if "he
sys"em simply is no" opera"ing, follow "hese proced"res "o isola"e "he failing FRU (do no" isola"e FRUs
"ha" have no defec"s).
Verify "ha" all a""ached devices are s"ppor"ed by "he comp""er.
Verify "ha" "he power s"pply being "sed a" "he "ime of "he fail"re is opera"ing correc"ly. (See Power sys"em
checko"" on page 28)
1. T"rn off "he comp""er.
2. Vis"ally check each FRU for damage. Replace any damaged FRU.
3. Remove or disconnec" all of "he following devices:
a. Non-ThinkPad devices
b. Prin"er, mo"se, and o"her ex"ernal devices
c. Hard disk drive
d. Ex"ernal diske""e drive or op"ical drive
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Hardware Main"enance Man"al
FRU or ac"ion, in seq"ence
Sys"em board.
1. Resea" "he LCD connec"ors.
2. LCD assembly.
3. Sys"em board.
1. See impor"an" no"e for LCD-rela"ed symp"oms.
2. Resea" all LCD connec"ors.
3. LCD assembly.
4. Sys"em board.
LCD assembly.