Just bought this Sony Vaio from a friend who used it twice in the last 3 years. I let another friend borrow it and it came back with a charger that had the cord ripped out from the box part and also it had a dead battery. So, I had the charger fixed and when I plugged it into the laptop, all I got was a spark. No charge to the battery and it didn't even get enough juice to power it on. So then I got 2 new chargers, neither of them worked, we tested the AC jack on the laptop; it seemed fine, I took battery out and did all those little tests to drain every bit of power and then plug it in; NOTHING!! I even replaced the memory and the CMOS battery; laptop is still lifeless. So now what.... How do I know if it's the battery or if there is a short circuit in the motherboard? Please HELP!!