PC "No Signal" Randomly? Help?

[Nathan_GamingUK]

today i was play GTA 5 and about 30mins into playing my screen said "No Signal" after waiting for 10-20secs it then came back on,

i could still hear game audio while this happened.

 

later on through the day i was browsing the internet and then my tab crashed displaying a crash message saying something about ram,

if the ram is causing this then i guess its ok as i have made plans to buy 24Gb (6x4Gb Kit) of Corsair Vengence.

 

My Specs:

R9 270

12gb Of Kingston KVR1066D3N7K2/8G 

900w PSU

Asus p6x58d-e - Motherboard

i7 930 @2.8Ghz

120gb OCZ agility 3 SSD

 

I will attach the image of what i seen on google chrome with the crash message.