want to fix the power supply of my motherboard alienware m18x

hi every body,

for the second time the motherboard of my m18x die. I changed it one year earlier. On yesterday, when I connected the power supply to the laptop, the small blue light around the connector turned it off and I eared something like a "TICK"at the same time (short circuit) it was exactly the same symptom for my old board.

I'm tired of buying a new motherboard (about 300$) and I would like repair one (or both) I have but I don't find the data sheet on google... number part is LA-6571P, I think that is from compal but not sure... If someone could help me? thank you.