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Friday, July 3, 2015

wistron ds2 intel dell inspiron 1525 dead sovled

hallo dear all ,,,,
toady i have repaired dell inspiron 1525 laptop 
costumer came and told me my laptop suddunly off after raining 
i have collect laptop and after day i tottaly forget its in a water damage board
for my habit opened laptop and check to start not see on pysicaly 
but i find problem 
lets seen how ,,,,,,,,
when open laptop check all coil impendence its almost good or not problem so 
attached pwr unit its not getting load 0.000 amp...
 
first check dcbatout its a 19 volt ok then check for stand by volts 3v and 5v its not generate 
so check regulator ic tps51120 pinout 
22 feet 18v ok  ,,2,7,20and 32 feet 5v its ok ,,19 feet vreg3 =3.3v and 21 feet vreg5=5v..  vref =1.99v its also ok then last check enable signal of regulator is on feet 12 and 29 its 3V/5V_EN is it 0v   ...
 
so 3V/5V_EN is coming from that circuit 
 
so its coming through S5_enable..
 
so s5_enable  is coming from i/o ic lets see here ,
 
its 15 feet its 0v   so check i/o vcc pin it all get 3.3v then check ECRST ITS 0V  and RSMRST also 0v ..but when i see on i/o ic its little bit dry due to water . 
20150701_162355[1].jpg (1.74 MB, 下载次数: 0)
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so i want to replace i/o ic but when remove i/o ic there is find a fault it a track missing due to water..here is damage track of i/o ic feet 101 , feet 102 its a AVCC and last one is feet 104 its a VREF ...so i/o ic did not get this voltages so i jumper first and insert own i/o ic and problem sovled ....thanks