[SOLVED] After adding a second monitor, my screen flickers in a way reminiscent of a faulty cable when playing some, but not all games.

[Athyrn]

Description of Original Problem: I've had my computer for about a year and have always gamed on an AOC CQ27G1 27' @ 1440 144Hz without issue. Most games at ultra settings. Yesterday, I added a second monitor (1080 60Hz) to my computer and ever since then, I've started getting VERY bad screen flickering in random games. The screen flickering doesn't appear to be a VSync type of flickering. It looks as if someone started violently wiggling my DisplayPort cable. My audio runs from the monitor as well, and the audio cuts in synchronization with the display flickering. video example

Computer Type: Custom

GPU: XFX Radeon RX 580 8GB DDR5 | Model No. RX-580P8D. Not overclocked.

CPU: Intel i3-4130 @ 3.40GHz. Not overclocked.

Motherboard: ASRock Rack H87WSA-DL

RAM: CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600

PSU: Corsair RM 550x; 550 WATT

Operating System & Version: Windows 10 Home 1909 18363.592

GPU Drivers: 19.50.19.19-200228a-352369C-RadeonSoftwareAdrenalin2020

Chipset Drivers: 10.0.18362.387

Background Applications: Steam, Chrome, GOG, Rockstar Games Launcher

Troubleshooting:
Swapped cables from DisplayPort to HDMI and back. Unplugged secondary monitor. No discernible difference.
Ran ATS in OpenGL, Safe Mode, and Direct X. OpenGL provided best results. Still screen flickering, but less frequent. Not playable.
Ran games in windowed/full screen. Ran games with full screen optimizations disabled. Disabled/enabled VSync. No discernible difference.
Downloaded Windows Media Creation tool. Formatted HDD and SSD. Reinstalled windows fresh.
Uninstalled GPU Drivers. Reinstalled.
Installed monitor drivers after factory resetting monitor.
Power cycled machine.
Set main monitor to all refresh rates between 60 Hz and 144 Hz

Notes:
Screen doesn't flicker when doing anything outside of video games
There was no flicker prior to the addition of a second monitor. Each of the games listed could run at or near max settings without issue.
Audio, which is connected to the impacted monitor, cuts out in synchronization with screen flickering.
I've had this computer and most of these games for a while now. This issue has never occured prior to the addition of the second monitor. Removing the second monitor does not seem to fix the issue, though.
When launching games through Radeon Adrenalin, Radeon Adrenalin does not recognize any performance issues.
Nothing seems wrong in Task Manager when the games are open.
No integrated graphics

 

[Phaaze88]

What likely happened:
-adding additional monitors of different native refresh rates causes a desync issue. Resolution doesn't matter.
-adding additional monitors also causes power consumption to go up.

It looks like you did the usual troubleshooting methods, but no fix.
When you uninstalled the gpu drivers, was that done using Display Driver Uninstaller?

Crazy thought, but it looks like plugging in the 2nd monitor screwed with the gpu itself somehow...
Sucks that the motherboard doesn't have HDMI nor DP - I'd ask you to try running the monitor off the cpu's Igpu to see if it still flickers.

 

[Athyrn]

What likely happened:
-adding additional monitors of different native refresh rates causes a desync issue. Resolution doesn't matter.
-adding additional monitors also causes power consumption to go up.

It looks like you did the usual troubleshooting methods, but no fix.
When you uninstalled the gpu drivers, was that done using Display Driver Uninstaller?

Crazy thought, but it looks like plugging in the 2nd monitor screwed with the gpu itself somehow...
Sucks that the motherboard doesn't have HDMI nor DP - I'd ask you to try running the monitor off the cpu's Igpu to see if it still flickers.

Thanks for the reply! Believe it or not, it turns out it was an issue with the monitor itself. At least, that's most likely the case. I called AOC Support and ran everything by them and they said that it sounds like a monitor issue and they're sending me a new one! All's well that ends well!

 

[Phaaze88]

Sweet! Best of luck to you.

 

[Ralston18]

That is good.

However, I would be a bit leery of that 550 Watt PSU.

It may no longer be up to the power requirements being demanded by the computer and components.

Also, if there has been no recent maintenance then power down, unplug, and open the case.

Blow out dust & debris. Reseat all cards, cables, RAM, jumpers. Ensure that all are fully and firmly seated.