Hi everyone,
i'm from Italy, and i'm new here.
I'll try to explain my problem as best as i can.
A friend gave me an asus K55DR (motherboard model K55DE rev 2.0) with black screen and fan at max speed.
As soon as he gave me the laptop, i tried it, it started up correctly (fan at max speed) but after a min the screen become black, then it remains black forever.
Tried to replace thermal paste, now fans goes at normal speed, but screen remains black.
Tried to reflash bios with some dumps found on internet, issue remains, so i tried to replace FCH two times.
Now the laptop doesn't power on at all, no fan, front led of power light up for 1 sec, then nothing (if you want to see it lighting up again, you have to disconnect and reconnect power plug or battery).
Power button doesn't work with AC adapter (as soon as i connect power plug, power led light up for 1 sec then nothing), but works with battery (as soon as i connect battery, no led light up, but when i push power button, power led blows for 1 sec then nothing).
Tried to put back original FCH, same issue remains. Tried to reflow CPU socket and replace GPU, same issue remains.
Can't find any short on the motherboard, no heat.
Some voltages are present, such as Vbattery (10.65V) and Vacadapter (19V), vbios, 5V etc....
Just noticed a strange thing...if i measure resistance across capacitors on top of FCH, only 3 caps are in short, the others are good.
If i desolder FCH the caps on top are not shorted anymore, so something is short on the motherboard (i suppose those 3 caps shouldn't be in short).
Please help guys