Toshiba P105-S9339 Nvidia Go 7900 GS restarts in 3d mode

Hi folks,

I have a P105-S9339 Vista notebook that I bought in 2007. Replaced hard drive with a fast disk, installed XP, found drivers despite nothing being available for XP on this vista model. Took about 2 days, ran great for two years. Played good games on the road, worked well. Only loss was the fingerprint scanner...

In October I started to have restarts whenever I launched a game, even those I had played successfully before. 2d works great, but any switch to discrete 3d mode and the computer restarts.

Pulled it apart, cleaned it, checked the fans and connections. All looked good. Put it back together, booted it, tested, 3d mode crashed.

Pretty sure the NVIDIA Go 7900 GS is fried. Been looking for a week for a replacement. Any ideas? Any ideas what may fit in that discrete PCI-E slot?