Question Why does my monitor have horizontal white lines and a dark bar across the top?

[hugomathews]

Whilst i was playing a game my screen suddenly got white horizonal lines across the screen mainly on the right half. When trying to troubleshoot this I found that when changing my refresh rate from 144hz (what i have always used) to 100hz the lines dissapeared. I tried reinstalling my graphics card drivers but it didnt fix it. I also found that when unplugging my monitor from the computer that there are no lines on the no power source screen, A snip of my screen also doesnt show the white lines. I am not sure whether this problem is with regard to my monitor or graphics card having issues. If anyone knows and could help me that would be awesome.
I have a Benq XL2720Z.

Thanks

 

[rgd1101]

make and model of the psu and gpu?
test with a different cable?

 

[hugomathews]

make and model of the psu and gpu?
test with a different cable?

I have an asus strix 2070 gpu. Not too sure about the psu. I dont have another cable to try at home i dont think.

 

[hugomathews]

make and model of the psu and gpu?
test with a different cable?

I just switched to a HDMI cable and I still have the same issue