Hello, I have a problem with my Acer Aspire 9820G. The problem is, that that the computer turns itself off after 2 seconds or occasionally runs for a minute or so but turns itself off again when I click on any icon. I have already cleaned all the dust from the cooling system and added new thermal paste to GPU and CPU, so I doubt that the problem is overheating. I have also replace HDD but the problem remains.... Please help!