my mobo fails--on two machines! Coincidence?

I own three Gateway MT3419s. Within weeks of each other two of the machines overheated and died. One of hte machines had previously been returned to Gateway for overheating (within a couple of months of purchasing). Called "lifetime gateway support" who promptly diagnosed as a fried motherboard $499 your bill...thanks for calling.

Took the machine to a local shop who commented that Nvidia recently admitted to providing some bad graphics cards to Gateway.

Could the be the cause? If so, how do I get Gateway to replace the motherboards in both machines, which are just over a year old.

Should I take any preventative steps with the one laoptop that has yet to die???

I appreciate your help and advice!

Here's the part info on the motherboard:

4001189RMotherboard w/NVIDIA C51MV w/o 1394 (FRU)

 

get a laptop cooler from newegg and file a complaint to gateway to aknowledge the faulty mobos

 

if the gpu is the nvidia 8600m gt. You have got 2years warranty and gateway has to repair it free of charge. if they don't, threaten to sue them.