Mac Pro won't play anymore. Video card issue?

[Kwackman]

Hi,
After many years, my Mac Pro (mid 2010 Westmere 5.1 6 core) has thrown a wobbler.
Last night, the screen went odd- covered lots of small coloured squares with the desktop bareley visible in the background. I was playing a tune in iTunes at the time. It continued playing but wouldn't play the next tune as it normally would.
It wouldn't respond to the keyboard, so I forced a shut down.
It rebooted OK, then the same thing.
Then it wouldn't boot, The start up chime kept repeating every 3 seconds.
This morning, I opened it up and hoovered out the dust etc (hoping for an easy answer!), but it still won't boot, and the start up chime still repeats every 3 seconds.
Somewhere on the net it was suggested the video card may be faulty.
So, I took the video card out, and started it, and it it only chimed once (as normal) and I could hear the HD working away as if it was booting normally. Of course, with no video card, I can't see any evidence on the screen!
So- that is why I suspect my video card has died.

Other stuff- I swapped RAM as repeating chimes is an indication of faulty/no ram, although apparently this gives a 5 second repeat of the chimes, not 3 seconds!
None of the boot up key strokes worked, resetting PARM etc, as it never got beyond the 3 second chime loop.

SO- The video card is a Radeon HD5770. It looks like I can still get them on eBay etc.

In the short term, does anyone know if the video card out of a previous MacPro (2008 3.1 model) which is a Radeon HD2600XT would work? I'm tempted to try, but don't want to cause any further damage.

Any info or ideas are welcome.
Thanks.

[ConcertinaChap]

I'm sure you're right about the video card going belly up. On your last question, I don't know but I would suspect not. I can't see why your Mac Pro would have a driver for the card installed.

Re the Radeon HD5770. If I were you I'd just do a bit of due diligence first as Apple have a history of using customised versions of otherwise established parts (the Xeon processor in my iMac Pro being a good example as its clock speed doesn't exist in the retail range). Otherwise that sounds like your best bet.

CC

[Kwackman]

Thanks for the reply CC.

On your last question, I don't know but I would suspect not. I can't see why your Mac Pro would have a driver for the card installed.

True, and I'm not going to try in case it releases some magic smoke and break 2 machines!

If I were you I'd just do a bit of due diligence first as Apple have a history of using customised versions of otherwise established parts

Yeah, good point. I'm chicken and will buy one specifically for a mac.

I might go for an upgrade to a card Apple will allow to run Mojave on, in case I want to upgrade to Mojave in the future. But it'll be a Mac version.

[Kwackman]

Update.
The video card from my old 3.1 MacPro (Radeon HD2600XT) DOES work in a 5.1 MacPro.

That confirms that it is a video card fault, which is good to know.

[ConcertinaChap]

CC