I have a Dell XPS M1530, Service Tag: <ADMIN NOTE:Service tag removed per privacy policy>. I had an technical problem with Nvidia BGA GPU Chipset (nvidia geforce 8600m gt). And there are no Dell local support to my device model.

I sent my laptop to a local assistance and they suggest me to replace the Chipset. But the model/ partnumber written on the Chip was unreadable, I just see this:

Nvidia - U802c279 0809A2 - S Taiwan - P42354.00W

I found two models off Chipset:
G86-630-A2
G86-631-A2

Could anyone tell me what is the correct Video Chipset model?