Toshiba P100 JR1E will not boot at all.

Question

I bought a Laptop for my wife and she said it was doing a self bios update and half way through it went dead now it won't boot at all. I replaced the nVidia 7300 go with a 7600 from the same model and it still won't boot. All I get is a black screen and the hd lite flashes 3 times and stops.. I paid 2500.00 for it from London Drugs and as a result of them being " it has to be user error" and not taking responsiblity for their products. So now I need to Know how to fix it with out selling my first and possibly second born.