mrtwing :
do the inductors degrade on the 8800gtx aswell? because its starting playing up thats why i've bought the 280gtx off ebay its runs windows fine but give it battlefield 3 it dies the second you get ingame online the screen goes purple and then the computer shuts down
Anything that uses the same type of inductor which includes many of the high end cards of today. The good news is that they can be replaced but finding the same rated inductors of the same type is almost impossible. You can use a different type of inductor and can mix but they won't fit under the stock cooler. Using higher rated inductors that are in the safe range for what the card can handle will improve overclocking and in general stability. The problem with these inductors is that their windings are very fine and thin. When they overheat and the insulation begins to fail they burn out like a light bulb. When they do that they kill the circuit and no current can pass through it. The typical inductors that people have been used to in the past that were simple wire around a ferrite core those keep the circuit when they fail but get very hot. There isn't a lot of detailed information in one place for people to look up but there are little bits and pieces of info scattered around online.
The inductors in the 8800gtx are not as heavily loaded as the inductors in the gtx280 and it gets a lot worse in many of the high end fermi cards. A lot of the high end amd/ati cards have the same problem while low end don't use the same inductor. It is best to go with non reference cards that use a custom pcb but cooling can sometimes be a huge pain.
As for the gtx280 I found that keeping the fan around 80% helps and one way to find out if an inductor is dead is to touch it. If it wiggles then it had already shorted out, if not then it shouldn't move at all but don't be forceful with them as they are also fragile. The ferrite surrounding the coil and sometimes a resistor can crack and break away leaving the coil/resistor in place hanging from it's lead. If it were not the crappy inductors I am sure that many gtx280 cards could overclock almost as good as the 9800gtx did. The good news is that the mosfets used are far better than most cards including many of the new cards.