Question Dark static diamond pattern appears on screen when using high refresh rate

[Lifecore]

Hello guys,

Monitor displays colors fine until 120 Hz (100 Hz is setting before, I didn't fine tune). Then static black diamond pattern appears. 144 Hz worsens the problem and colors get a little darker. Nvidia control panel settings are the same on every refresh rate (32 Bit, Full dynamic range, Color depth, RGB, Resolution is the same, Freesync makes no difference). Monitor settings like Response time, Energy saving, 1ms motion blur reduction, Black stabilizer, Freesync, Brightness, Contrast make no difference. Monitor (34UC79G) is connected to PC via Display Port. My first guess would be to buy a new cable, what do you think? Picture is below.
Lets solve this and help someone with the same problem , I found nothing about it on the internet.

Picture

Regards,
Lifecore

 

[gamerk316]

Can't view at work; most likely cause would be the DP cable you are using isn't rated for the bandwidth necessary for a higher refresh rate. Simple test would be to try and lower resolution; does 720p/120 work? If so, that would make me suspect the cable. If not, then something else is likely going on.

[I'm assuming the resolution/refresh combination is supported by the monitor.]

 

[Lifecore]

That DP cable came with monitor when I bought it. 1280x720 144 Hz, same problem.

Ok guys, I tried:
New DP cable (1.2 version)
Booting Ubuntu
Changing Display ports on graphic card
Problem is on HDMI also (120 Hz is max I can output, 100 Hz and lower has no problems)
Another laptop using HDMI cable (120 Hz)

The only thing left to try is buy a new power supply for monitor. What do you think?

 

[Lifecore]

After almost a year, it's sad that there's still no answer.