Geforce 8800 GTS Problem

Hi guys!

I have a problem with my old Geforce 8800 GTS.
It's been re-worked and cleaned by a good friend of mine (used to work in a computer shop, he know's what he does).
when he tested it, everything was fine, no problems occured. But whe I put it into my test machine, it took 30 secs and it started to behave some kinda weird.
fan speeds up step by step to full speed while idle, even with the latest available drivers installed. Tried to check the temperature with GPU-Z, it flips from 48C to 168C to 200+C back to 48C in a loop.

I already checked it and changed the thermal paste AGAIN, same problem.
It just flips from 0C to 128C back to 0C...



Any idea how to fix this?

Does the heat sink feel nice and tight? Some older gpu require a thermal pad rather than paste as the heatsink is designed to accommodate the thickness of the pad. It's a while since I've come across one like that though.

It's fitting perfectly.
the pads are only on the ram modules and they still fit, too.

that's an odd one, unfortunately sounds like an issue with the thermal sensor, you could try using 3rd party software to control the fan speed manually but would be interesting to see if the card is under clocking its self to protect it if it thinks the heat is sky rocketing?

also an option worth looking at is a firmware update if one is available, while its not a fault due to the card previously being fine, sometimes a firmware update can just reset everything.

I used msi afterburner to lower the speed manually, otherwise I would be deaf right know...

It's not underclocking itself, just keeps on working at full speed.
I think the sensor is broken, so before I try anything else, I put it back in the box and leave it there.

SpruceGuy has an AMD card that does exactly the same thing, oddly enough it has a large cooler on it which makes the card sag a little, if you keep it propped up the problem is night and day better but still shows its head occasionally. The heat sink gets good contact with the CORE even when sagging a little so not sure what causes it to behave like this.

but a few minutes fiddling with the afterburner fan graph profile has had it running for over a year quietly with no issues.

take a look at the video to see what it doing...
does it play the video or do you have to download it ?
let's see...

ok, no video.
filehosting service is stupid...

uploading It to youtube seems to be the best way for embedding it if you have an account, I just upload mine to the HwH youtube but unlisted so it doesn't show on the channel but still embeds fine on the forum

I'll try to login to yt....

Let's see if it works this time...

This is an issue with the PCB board bending due to the weight of the cooler and it doesn't seem to effect the workings just sends wrong signals as my fan ramps up on occasion and I think when the board twists it upsets the thermal sensors rather than affecting the cooling properties of the sink. but my card doesn't hit 128 degrees or not that I have noticed. My card is the Nvidia GTX760 2Gb. Ill try running GPU-Z and see how it fairs under a 3D test and I will post up my results.

It isn't even 128C, that would be killing it. The lower temp is correct.
This happens even when mounted upright in my test tray...