GTX1060 now refuses to detect Displayport monitor

[beatle]

Earlier this year I had a bear of a time getting my MSI GTX1060 to detect my AOC AG271QG properly. I fiddled with multiple driver revisions and settings, but eventually it came out okay and I've been using it ever since. Yesterday, however, I decided to pull my CPU cooler and reapply my thermal paste as I saw temps were getting higher. All went well, but when I turned the box back on, the monitor would no longer detect in Windows. It comes up during BIOS and during the initial load of Windows, but apparently as soon as Windows is about to display the desktop, it dies and says "no signal."

I have a second monitor connected via HDMI through a receiver that also has my speakers through it. That monitor works fine. I've tried uninstalling drivers, cleaning them with DDU via Safe mode, running the card with no HDMI connected to it, powering off the monitor, resetting it to defaults, checking if the card's firmware is up to date (it is), and unplugging the monitor and desktop and letting them sit for a while. Unfortunately I need DP for GSync to function. I've just about run out of ideas aside from selling the card.

 

[VirtualLarry]

If you have a display connected via HDMI, Windows seems to "prefer" that device as the Primary Display, especially if it's connected / enabled / powered-up at BIOS and Windows boot time, and DisplayPort devices play second fiddle.

 

[beatle]

That was sort of my thought as well, but even with the HDMI monitor unplugged from the card, Windows still refuses to detect it. It will only display on my DP monitor in safe mode.

 

[beatle]

I also tried updating my BIOS as it was over two years out of date. No joy there. Then I did another driver clean from safe mode with the DP monitor connected. It seemed to work and I rebooted into windows. It was working with the single monitor for a bit at 1024x768, so I bumped the resolution to native. Still working. A minute or so later the monitor just goes blank again.

At this point I suspect there is something up with the cable since I did nothing on the software side to provoke the failure. I fished the unused DP cable out from the monitor box and tried it. Bingo. The DP monitor popped back to life. I'm guessing the other cable was already on its last legs and unplugging it when I went to do the thermal grease pushed it over the edge. The BIOS screen and safe mode required a lot less bandwidth than native 1440p and 144hz so it didn't trigger a failure.

The cable was a 10ft gold plated one from Cable Matters, if that matters.

 

[24601]

Displayport cables are only rated to 3 meters for full bandwidth (which that monitor is most certainly using).

 

[beatle]

Blacksburg resident?

Maybe it's only 3m. I left my metric yardstick in my other pants.

 

[24601]

As in literally the slightest imperfection in that cable would cause it to stop functioning properly in your use-case.