why does my pc display keep flicker jumping

[moddinggamer66]

i am having a strange problem on my PC which has been happening since i bought it

every now and again (the frequency of it happening is random)

my monitor keeps doing a jump sometimes several times in a row which looks similar to a loose cable connection jump

 

very rarely the screen also will have a quick color flash usually green or red

 

for some reason these issues do not happen if the display is set on a lower resolution then 1920x1080 60hz

 

pc specs

custom built (the shop built it for me)

(no overclocking)

windows 8.1
intel®core i7-4770 CPU @3.40GHz
memory ram 16.0 GB
64-bit op
graphics card AMD Radeon hd 7900
motherboard asusR z87-a: ATX
power supply corsair 550w vs series vs-550 pov

 

any help