So for about some days ago I tested my XFX 8800 GTX (was not working at all) through some benchmarks after I overclocked it a tiny bit. One mistake for doing that, the way I repaired the card is called "re-flow soldering" and basicly you heat the lead connections in the card up to a certain point where they melt and re-join the cracks in the lead.
http://en.wikipedia.org/wiki/Reflow_soldering
This procedure is not however fault free, as I experienced yesterday when the card was pushing more after playing some games. I think the heat from the card may have made the card in-able to play higher graphics. The card still work fault free while playing for example Minecraft.
Now when I try another game with higher graphical demands the card shuts down and Windows puts the card in a "safety mode". And the screen starts to flicker.
I will however not be without good graphics for too long, as my friend is giving me another card to play with
a NVidia 9800GX2, I just have to fix it
So to the point of the thread, re-flow soldering works if you don't push the hardware to its max potential will probably put it back in the same case or worse then before. This method is used on many types of electronics, for example RRoD on Xbox, YLOD on PS3, faulty hardware on cellphones. As for the PS3 and 360, don't do it, as the games are designed to push the hardware to the ragged edge.
Re-flow Soldering can be done with a oven or heat-gun just be cautious.