Sapphire HD 5770 1GB faulty temp sensor

[Jiniix]

I have a Sapphire HD 5770 1GB (model#: 11163-02-20R) that has a faulty temp sensor.

In GPU-Z it reads three different temperatures.
At idle it would be like: 42C, 48C and 125C.
At load it would be like 72C, 78C and 125C.
The 125C would never change. I'm 99% sure it was faulty (and not acutally being 125C at a particular spot on the card) and just ignored it. Now the card won't work, as when you boot up, the BIOS posts etc, but after a few seconds the screen goes black and a red LED lights up on the card. Googling tells me the LED means overheating.
I've tried running it in CrossfireX as the secondary card and plugging the monitor into the working card (I have three of these exact cards) and AMD will just tell me that CrossfireX isn't available.

I was wondering if I could either:
Remove the temp sensor on a hardware level, or
Modify the BIOS of the card to ignore it completely.

Any other options that works is of course accepted with great appreciation.
The card is, obviously, a few years old and has no warranty or anything. And it doesn't work at all right now, so it's either fix or trash, meaning that methods that break warranties and such are OK.

Thanks in advance, Jiniix.

 

[p1987]

I have a 4850 and after changing to a third party cooler, it also would post and a black screen would appear.

Consider looking into cooking the card. I haven't tried it on my faulty card but I have heard that it can bring back cards to life; reheating to solders.

Hope this helps.

Regards

 

[Jiniix]

I read about that technique back when my old NVIDIA 9800 GT broke.
Actually, for any Scandinavian people out there, Komplett.dk/se/no (where I bought the card three years ago) agreed to fix it for free.
As I've said, they aren't forced to do it, it should be out of their reach. But they're a nice company