HD7970 Giving Code 43 in Device Manager/Drivers Won't install

[KingOfComputing]

I recently bought a used Sapphire HD7970 GHZ Edition 3GB, which I got quite cheaply but it did need a little work doing to it.

Firstly the fan cable had in the hands of the original user somehow snapped and they had repaired it to run on a normal motherboard 4 pin fan lead. When I got the card the DIY repair had practically fallen apart but I was able to reconnect it all and both fans do spin (not sure if they are running fast enough but they are spinning and moving a little bit of air).

Anyway, second problem was the card had one of the two BIOSes flashed with an incorrect BIOS (seller said it was a BIOS of a different model of 7970) and needs reflashing.

So I fixed the fan lead, verified at least some cooling was happening and was able to get to Windows (8.1 64 bit). However in the device manager the card has the yellow exclamation mark and says "Windows has stopped this device because it has reported problems. (Code 43)". I tried installing the AMD drivers regardless but they fail with warnings though still prompt to reboot, I rebooted on the hope they might have still installed but next thing Windows blue screens (well the Windows 8 version of it) and does this every time until I make it do a system restore then the card 'works' in that it outputs a picture but won't take the driver and hence (I'd imagine) would fall over if I tried to run anything more than 2D applications on it.

So why am I getting the code 43? Is it the BIOS problem, if so how do I switch to the good BIOS? (I couldn't find the physical switch on the card) or reflash the bad one so it will work?

Any advice greatly appreciated.

 

[dovah-chan]

Here is a guide to upgrading your GPU BIOS. I would also recommend completely uninstalling your drivers with this guide. Feel free to ask any questions if any come to mind.

(Thank the lord these guides were written X___X I refer people to them sooo much)

 

[KingOfComputing]

Thanks but after contacting the seller, I have confirmed the card was already set to use the good BIOS, which is the factory BIOS it shipped with. He said if the incorrect one was set it wouldn't even boot.

He did suggest some beta drivers to try but these have made no difference. I have also tried completely removing all traces of previous display driver installations both manually by deleting files from the locations and registry and with the display driver uninstaller tool as well but none of this helped, I am still getting code 43 in device manager.

I also tried running a benchmark (unigine heaven) to see if it was working at all but I just get a black screen with the mouse pointer so it looks as if all the cards 3D features have been disabled for some reason.

Does anyone have any further suggestions for fixing the card?

Alternatively is there any good diagnostic software for graphics cards that might be able to tell me exactly what is preventing the card from working?