Hello, I have this computer when I press the power on button the LED lights up for about 3 seconds only and after that the computer goes dead. The screen does not light up during these 3 seconds. The battery is fully charged and I have tried to remove the battery and connect it to AC power only. Nothing seems to turn on this computer. And the DC Jack is OK. I want hot air the motherboard but I don't know where would be the problem??? Anyone has an idea??? Tnx.