Question Second monitor flickers to desktop and back

[Ley]

Both screens are plugged with an HDMI cable to my GPU. Whenever I'm playing, the second monitor flickers, showing the desktop and back to the app it was running. That can happen many times a second or once in a minute.
Also, this happens when I'm running a game:

View: https://www.youtube.com/watch?v=5Jz1TPnCrSc&feature=youtu.be


These weird moving lines happened when I had my old PC too, and it's not a monitor issue. I've tried with another one and same issue. Hope it's not a defective GPU...

 

[Aria Qadir]

1. Use different cables like VGA, DisplayPort, etc.
2. If not, check your screen refresh rate. Play with it and see if it fixes it.
3. Check if your GPU is properly seated in the slot. Maybe put it in another slot.

 

[Ley]

1. Use different cables like VGA, DisplayPort, etc.
2. If not, check your screen refresh rate. Play with it and see if it fixes it.
3. Check if your GPU is properly seated in the slot. Maybe put it in another slot.

1. My second monitor only has a VGA port, I'm using a VGA to HDMI adapter
2. I think I've tried already, but I have no option to change the refresh rate. Max and minimum is 60Hz.
3. I also think it is, since I have no issues on my first monitor...

 

[Aria Qadir]

I am convinced that the problem is with your cables, either the VGA cable or the VGA-HDMI adapter. GPU is ok since your first monitor works just fine.

 

[Ley]

Thanks for replying. I'll see if I can swap cables and I'll let you know!

 

[Ley]

Update: I don't think it's the cable... I've tried with a couple

 

[Ley]

So I've tried again with another cable and I don't have those horizontal lines anymore, but the flickering is still there.