black screen when pc is still on

[pomkon]

several times i try to edit a 2mb paint file, and a few times using the chrome - the screen goes black but pc is still on

 

windows memory diagnostic shows no fault. however windows didnt show the whole desktop, only the top left screen was showing after restart. it returned to normal when i restart again.

furmark preset 1080p stress test was fine - it finishes within minutes (was it too short)

 

it went on a boot loop earlier before i encountered these problems, i reseated the gpu + ram and pc was bootable.

 

ryzen 1700x

x370 aorus gaming k7

zotac gtx 1060 6gb amp

avexir ddr4 2400 8gbx2

 

its a new pc