Hope this is not a repost, but...
Found this while ploughing through digg <Linkage> it appears that this blokes managed to get his 8800gtx working again by baking it in the oven for a while. The thread goes on for ages with other stories of success with other knackared hardware too.
disclaimer
Not tried myself (though might give it a go) and take no responsibility for loss or damage caused by attempting this in any way at all!!!
BrOw