Mac Pro 3,1: Faulty HD 5870?

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Level 4

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Mac Pro 3,1: Faulty HD 5870?

Hello all

I hope someone can offer some input on this. My main computer, a Mac Pro 3,1 has an ACD 23" connected to a HD 5870 (Mac version). The video card has worked flawlessly since I bought it (used) last year (I was very happy to find one) and I've been very happy with it.

Today I noticed that my screen keeps going black, just like that. I've two boot volumes - a 10.6 and a 10.9.5 - and it happens on both: After boot - from 20 secs to 10 minutes after - the screen simply goes black (the computer still functions). I have to force a reboot to get video back.

I've connected the display to my laptop and it doesn't go black which leads me to think that it's the HD5870. Is there a way to run a diagnostics or something like that to find out what's going on?

Thanks very much in advance for any input

Philip

Mac Pro 3,1-OTHER, OS X Mavericks (10.9.4), 2x3TB 2xSSD+Sonnet TempoPro ACD 23"

Posted on May 9, 2015 8:43 AM

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Answer 1

Best reply

lllaass

Level 10

210,411 points

May 9, 2015 9:30 AM in response to pullman

You can try running Apple Diagnostics

Using Apple Diagnostics - Apple Support

However, it does not find a lot of GPU problems. Also, since it works OK for a while, running the test when it is running OK will likely show nothing.

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Answer 2

pullman Author

Level 4

1,192 points

May 9, 2015 10:14 AM in response to lllaass

Thank you for the reply. I was also thinking the AHT (mine's a pre-2013 model). Then I had a duh moment and opened the bonnet to check - seems one of the power cables was ever so slightly out of the socket. Not a foggiest idea how that could have happened as I haven't done anything for months and the computer has worked fine. No black outs so far but I'll keep it running a bit longer tonight to see what happens. I guess it could make sense that it could cut the video if it didn't get enough juice.

Best

Philip

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Answer 3

pullman Author

Level 4

1,192 points

May 17, 2015 8:23 AM in response to lllaass

So now I've tried a bit more and the black-outs continue under 10.6 unfortunately.

As I understand it, the HD5870 isn't meant to work with the older Mac Pros but usually does. What I am not sure of is if there's an "oldest" OS X version that it can work with - do you know? I run 10.6 at the moment.

Thanks for any help
Philip

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Answer 4

The hatter

Level 9

60,990 points

May 17, 2015 8:46 AM in response to pullman

Is the Sonnet Tempo the only PCIe card you have? Try without.

Assume you tried Safe Boot and SMC Reset + NVRAM reset.

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Answer 5

The hatter

Level 9

60,990 points

May 17, 2015 8:48 AM in response to The hatter

Take a look at post #17 in this thread:

http://forums.macrumors.com/showthread.php?t=1880482

Quote:

I have a very functional Mac Pro 3,1 running Snow Leopard with a 5870 in it.

I wanted a decent Nvidia card but didn't want to upgrade the MP beyond Snow Leopard. I had an i7 Hack built with a GTX 770 4Gb Palit Jet stream and run it on Mountain Lion. Both play happily together. I would source a 5870 secondhand and start afresh with a single Snow Leopard build before reinstalling Bootcamp on a new drive.

Shove the GTX680 in a Hack and run a newer OS.

5870s are still available: (has ebay link I had trouble pasting)

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Answer 6

pullman Author

Level 4

1,192 points

May 25, 2015 2:01 PM in response to The hatter

Hi Hatter, sorry for the delayed reply. I think you might be on to something about the Sonnet Tempo - it requires 10.6.8 and I run 10.6.

Tonight I downloaded the 10.6.8 combo update. But now I am in a bit of a fix because the screen went black during the installation process so I can't tell what's going on. Before the screen went black I saw that it was verifying the update, then after a few minutes there was a Bong (restart) and now the computer is apparently waiting for input. It's years ago since I last installed Snow Leopard so I don't remember the steps, meaning I can't Enter or Tab myself through the installation process (which would have been risky in any event).

So I suspect I'll have to hard-reset the computer and quit the installation. Then re-install my SuperDupered 10.6 clone and re-download 10.6.8.

Is there any way for me to install from my Macbook (running 10.9) so that I can see what is going on? I don't have another screen or video card unfortunately.

What a mess...

Many thanks in advance

Philip

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