Need help troubleshooting

[Megamuffin]

My specs:

Core i7 4790
Radeon R9 270
Asus Z97-K
Aerocool E78-730
8 GB of DDR3 @ 1600

for the past about 2 months all of a sudden my PC will freeze with the sound repeating, i wasnt sure what it was im no expert in PC's i know how to build my own PC but im a gamer i wouldnt know where to start with trouble shooting. My Motherboard and CPU are brand new i got it 3 days ago

so motherboard and CPU cant be the problem since it continued freezing afterwards.

i decided to check my RAM i had 2 x 4gb sticks, i tested them both booting my pc with 1 then the other. first one my pc didnt boot, second one i got a blue screen with an error thats related to RAM STORAGE_ something i googled it it has to do with RAM or failed HDD

So i replaced those with a new 8gb 1600 ram stick

but now still getting occasional freeze, but now a new problem has come up since i got my new CPU + motherboard.. my screen randomly loses signal.

Ive googled that the possibilities are: my GPU is over heating, but ive got HWMonitor open its at 30 C atm idle, and my screen loses signal randomly not during games, i can be watching a youtube vid it will lose signal. so i dont think its a GPU temp problem

Ive done a fresh install of Windows 10 reformatted and everything to prevent driver issues so i dont think it can be a driver problem.

What else could it be im running out of ideas
Heres idle temps: http://i.imgur.com/e2GGekd.jpg
seems abit low but clearly there isnt heat problems even if its 10c off or something.

i dont mind replacing parts but i want to replace the right part ive ruled out it cant be CPU/Motherboard/RAM..
how do i go about troubleshooting the rest..?

 

[DanDango]

So new cpu, new motherboard and new ram, best to check your power supply.

 

[Megamuffin]

So new cpu, new motherboard and new ram, best to check your power supply.

how would i test that im no electrician and as far as im aware you cant test it with software and i dont wanna go and blow my psu because i have no clue what im doing

 

[Megamuffin]

how would i test that im no electrician and as far as im aware you cant test it with software and i dont wanna go and blow my psu because i have no clue what im doing

update: after a fiddling around abit, i have narrowed it down to my PSU or GPU but i think its the PSU because i got fed up yesterday rebuilt my pc, took everything out cleaned my older parts properly then reformatted again, maybe all the restarting caused some crucial files to get corrupted.

i also decided to leave my GPU out on the reformatting process maybe it was my GPU, and used the onboard gpu to reinstall windows which went well reinstalled no problem.

i put my GPU in after the install problems again... i take it out restart then i even get problems with the onboard graphics it all of a sudden started flashing colours. so im getting a friend to borrow his PSU just to test for a few hours. see if theres any improvement