I want to tell my experience with this problem. I bought a Sony Vaio VGN-FZ11Z in 2007. I think this laptop has very good features, I mean, I have bought 4 laptops since then (Packard Bell Easy Note AGMM0, Asus UX32V...) and I recon this is the best by far, even though is older. I have passed long hours using this laptop until last year, when the video card stopped working. I had no time or tools for fixing it, so I took it here: http://www.humedalinformatik.com, to be fix. They gave me 2 chances: a new motherboard (220 euros) or reballing (170 euros). I took the first one, because I tought it would be more reliable (as it was "brand new") and the difference of price wasn't too much. After the repair, the laptop was working fine for 6 months and then the nvidia chip broke down again. When I went to the repair shop, they told me that the guarantee only last 3 months and that the "new" motherboard wasn't original, even more, that mobo COULD have been reworked. I was shocked. I went to the official repair center of Sony in my city and they told me that the mobo cost 470 euros. I'm not gonna pay it for sure. Now I have the 2 mobos with the nvidia ruined and a very good laptop unuseful just because some jerk cheated on me. But I won't give up!!
First of all, I have to strip the chip off. I'm planning to do that with hot air, and then we'll see.