Random red flickering lines appear on screen after GPU change

[ferocity]

Hi would appreciate help troubleshooting a pc issue i am getting. Couple days ago i bought a used gpu online and installed it into my system. Did some initial testing with benchmarking tools and everything seemed to be working fine.

However, today when i am using my pc, i noticed red flickering lines started to appear on screen randomly. Starting with 1 or 2 lines and then slowly more will appear. These lines would go away once i restart the pc and then they will just reappear randomly.

I tried taking screenshots and these red lines do not show on the screenshots, so i am inclined to think the problem is with my monitor and not the gpu. However, as i do not have a spare monitor or gpu(already passed my old gpu to a relative) on hand for further testing, is there any other surefire way to troubleshoot and isolate the problem?

 

[jtjt00]

Connect a laptop to the monitor and see if red lines appear?

 

[Koenig168]

Connect to iGPU.

If the problem persist, then it is the monitor.

 

[ferocity]

Thanks for the previous replies. Forgot to mention i am running my 60hz monitor overclocked to 76hz but i never had any issues with my old gpu.

I tried switching out to a different hdmi cable and reverting to 60hz and there hasnt been any flickering lines for the past 45 mins(fingers crossed). Looks like its also high time for me to change the monitor to something with higher refresh rate.

 

[yusoffb01]

yes unofficial refresh rates can cause flickering