Help - My Mac Pro (under El Cap) won't recognize my video card anymore!

[PowerMac G4 MDD]

Hi,

So I have a 1,1 Mac Pro running El Capitan. I had been using it just fine for some weeks, but now I've run into some spontaneous issue.

I was using my machine today (with my Radeon 5770), and I decided to change the refresh rate on my monitor. Well, the mouse pointer started skipping across the screen/lagging, so I was forced to just restart my machine. After replacing the boot EFI files again (since I couldn't boot from the darn drive for some reason), I was able to boot back into my desktop...

HOWEVER, the OS no longer cares about my Radeon 5770. Expansion Slot Utility recognizes it, but the thing won't display a picture on any of my monitors. On the other hand, my 8800GT works just fine with it, and everything is displaying nicely. What happened? My other AMD card isn't working either. This all just happened in the blink of an eye.... any ideas?

 

[MacVidCards]

Using another partition or HD create a 10.8 or 10.9 or 10.10 install and see if your cards work there.

 

[PowerMac G4 MDD]

Using another partition or HD create a 10.8 or 10.9 or 10.10 install and see if your cards work there.

I have a feeling that my Radeon 5770 (that I passively-cooled myself in the most hack-job-ish way possible) died on me... . My little Radeon 6450 ended up working fine.

 

[pat500000]

http://www.apple.com/shop/buy-mac/mac-pro
here's your solution.

 

[PowerMac G4 MDD]

http://www.apple.com/shop/buy-mac/mac-pro
here's your solution.

Very funny.