That video card looks to be from 2009 or prior. It's done well. Try another.
It's been doing this since I reformatted about 3 weeks ago, it's every 15-30 mins and sometimes it reverts itself back, and sometimes it requires me to change the HDMI source from HDMI 3 to HDMI 4, thus bringing back a normal display. It's definitely not the TV as it's never done this whilst on my PS4 or watching normal TV.
I have tried a different HDMI port
I have tried a new HDMI Cable
I have tried adjusting settings on the TV
I have tried adjusting settings in Catalyst control pannel (ATI 4850HD 1GB GFX Card)
Any help would be amazing, thanks.