Strange issue I'm having with my Mac Pro 3,1. First, the specs:
Mac Pro 3,1
OS X 10.11.6
32GB RAM
Stock/reference GTX 680 GPU, flashed for boot screen, driving two 30" ACDs, latest NVidia drivers installed
480 GB OWC SSD for boot drive, two other rotating HDs
This is what happens on a random basis. It might be fine for several weeks, then start doing this:
Computer will start up with the "bong" as expected. Progress bar runs to about 2/3 of the way and the machine hangs. Pressing power button momentarily will get the "bonk" sound. Hold it down and the machine will shut down as expected. Restart will do the same. Resetting PRAM or going into recovery and running First Aid on the hard drive has no effect.
Here is what "fixes" it:
If I unplug monitor #1 before starting up the system will boot normally. I plug monitor #1 back into the GPU after booting and the login screen is present and all is well. Note that I was able to identify the "fix" with a previous video card, an ATI 5870 1GB that was also flashed for boot screen. I discovered this fix during troubleshooting making me attribute the problem to the (old) video card. As I was planning on replacing it with a GTX 680, I went ahead and did so, and for several weeks did not have the issue. Now it has returned with the GTX 680 as well.
I would add that at one time I was booting into recovery and reinstalling the OS which seemed to fix the problem. However, it would occur again after doing so, making me think that it's not an OS or software issue. That's when I discovered that unplugging monitor #1 would allow the system to start up normally.
I'm stumped.
MacDann
Mac Pro 3,1
OS X 10.11.6
32GB RAM
Stock/reference GTX 680 GPU, flashed for boot screen, driving two 30" ACDs, latest NVidia drivers installed
480 GB OWC SSD for boot drive, two other rotating HDs
This is what happens on a random basis. It might be fine for several weeks, then start doing this:
Computer will start up with the "bong" as expected. Progress bar runs to about 2/3 of the way and the machine hangs. Pressing power button momentarily will get the "bonk" sound. Hold it down and the machine will shut down as expected. Restart will do the same. Resetting PRAM or going into recovery and running First Aid on the hard drive has no effect.
Here is what "fixes" it:
If I unplug monitor #1 before starting up the system will boot normally. I plug monitor #1 back into the GPU after booting and the login screen is present and all is well. Note that I was able to identify the "fix" with a previous video card, an ATI 5870 1GB that was also flashed for boot screen. I discovered this fix during troubleshooting making me attribute the problem to the (old) video card. As I was planning on replacing it with a GTX 680, I went ahead and did so, and for several weeks did not have the issue. Now it has returned with the GTX 680 as well.
I would add that at one time I was booting into recovery and reinstalling the OS which seemed to fix the problem. However, it would occur again after doing so, making me think that it's not an OS or software issue. That's when I discovered that unplugging monitor #1 would allow the system to start up normally.
I'm stumped.
MacDann
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