[SOLVED] Help me diagnose instability with displayport. Software problem?

[lazarus]

So I am getting stumped here and not sure where to go as far as diagnosing this problem. The history:
I built my hack with a Gigabyte z97X-SOC board, GeForce 750 Ti, and a Dell 4K monitor. All worked fine when using HDMI. But when I would use the DP to get 4K at 60Hz, weird things would happen. Most notably when the system would sleep it could not wake up. When I tried it would shut down, and could not restart until I unplugged the DP cable. Then upon restarting all the BIOS settings would be reset to defaults. If I turned off the monitor before trying to wake up the computer it would usually be OK (but sometimes shut down anyway). This happened both on the DP from the video card as well as the built in DP on the mainboard.

So I thought it was a defect on the mainboard. Bought an Asus Z97-K.... and the same thing was happening. The BIOS resets on this board as well when it shuts down, and it (usually) does OK if I turn the monitor off before trying to wake it. Tried a different 4K monitor thinking maybe there was a problem with the monitor (the miniDP on the Dell didn't seem to work, so I thought maybe something was screwy in there)... and the same problem persists.

This is getting to be a very expensive troubleshooting operation. Plus it's a huge hassle to have to reenter all the BIOS settings every time it happens. Others with very similar builds have not reported these problems. I'm getting desperate looking for ways to figure out what on earth is going on here.

Thanks for any help.

 

[toleda]

Help me diagnose instability with displayport. Software problem?

BIOS resets on this board as well when it shuts down,.

The symptom is CMOS reset on shutdown, nothing to do with graphics/DP/etc.
Assuming Clover: set config.plist/KernelAndKextPatches/AppleRTC/YES

 

[lazarus]

Help me diagnose instability with displayport. Software problem?

The symptom is CMOS reset on shutdown, nothing to do with graphics/DP/etc.
Assuming Clover: set config.plist/KernelAndKextPatches/AppleRTC/YES

I will surely give that a try when I get home. If that is the culprit, it is odd that it only seems to happen under this specific circumstance (trying to sleep or otherwise crashing on DP only). I have literally never had this happen when using HDMI.

 

[lazarus]

Help me diagnose instability with displayport. Software problem?

So unfortunately that is already set to true, and has been the whole time this has been happening.

Also it sometimes seems to interfere with shutdown. If I try to restart, it won't, and will not really do anything until I unplug the DP cable. I can unplug the entire computer from the wall, plug it back on, and press the power button... and nothing. Then if I unplug the DP cable it powers on, and goes in to BIOS with the settings all reset.

I'd be tempted to try another video card if it hadn't done this same thing with the DP on the Gigabyte board as well.

 

[lazarus]

Help me diagnose instability with displayport. Software problem?

So I need to test things more, but I just put the system to sleep with DP plugged in, and it WOKE UP. I've been messing with a number of things to get USB working, but I think the relevant change here is that I used a different cable. Perhaps the one I was using was somehow shorting pin 20 or some other power issue, I don't know. I need to put it through its paces, but I hope this solved this mysterious issue.

 

[dahe]

Help me diagnose instability with displayport. Software problem?

Do you resolve it?

I have the same problem

 

[lazarus]

Help me diagnose instability with displayport. Software problem?

Yes, if it wasn't clear in my last response, it was a hardware problem for me. I had a bad DP cable. Once I switched it out the problem went away.