U2713HM, fuzzy in full resolution

Hi

My U2713HM display fuzzy and blurry if I use it in full resolution 2560x1440 60Hz. But in low res its fine 1080p. 

I tried factory reset, switch HDMI (HDMI work fine but only display 1080p,)

Uninstall graphics cards and clean install no luck, using dual link dvi cable , it was working fine for last couple of years, is it graphics card or monitor.

When i cold start computer it can display full resolution for couple of minute then its start flickering getting blurry. 

Thanks