Extremely hot 8800gt... please help

Im assuming 677rpm isnt anywhere close to the 100% speed it sais it is... Ive tried changing it with rivatuner who said it was 25%, but its not changing anything...

I opened up my case, low and behold the fan didnt even look like a fan, completely blocked with dust... Thats what you get when you travel for 2 years and come back to your PC i suppose... Cleaned that out and expected it to be fixed, but as i speak the idle temp is going from 61degrees C to 73degrees already, in about 4 minutes...

The card is clean right now, right?
So try to re-apply the thermal paste, see if that help or not...

+1 remove heatsink and old thermal paste. get AS5 thermal paste and read a guide how to use it properly if you dont already know, and re-seat heatsink with new thermal paste.

I reapplied the paste with silver based thermal paste, no change in temp... idles at 80degrees centigrade

Is there any chance it could be my PSU?

I'm curious...

1) You cleaned the fan, but did you clean the heatsink too?
2) Does the fan sound like it speeds up or not? Can you manually set it faster in MSI Afterburner?
3) If you remove the side panel of your case, does the temp drop?

Opened everything up and cleaned out the heatsink, let it all cool down for a full day, now it seems to be running fine... idling at 45, only went up 6degrees when i gamed... Hopefully this lasts!

Thanks guys

Hmmm, so I thought everything was fixed... Temps were perfect... Now my computer wont even turn on... I managed to turn it on once, and i got a no video error on my monitor... Now when i try to turn it on, I briefly get power, the fans turn on, and then turn back off... Dead PSU im guessing? How can i find out whats wrong when i cant even boot?

Could be a dead PSU, could be a short somewhere, could be a dead motherboard... unfortuantely this type of issue isn't easy. Check all connections and pins first and foremost. Make sure it's all be put back together properly.

If you can try a different PSU give that a go. If it doesn't help the situation, sounds like maybe the mobo died.