Many thanks for the replies, as well as the related suggestions!
Luckily I had a friend who brought two PSUs together with his current PC and after several (yet, thorough) tests it's clear the MB was indeed faulty. To be honest, I've thought about buying a second hand Z77 motherboard - but I...
Good day everyone!
I'm having some serious issues with my computer, and I can't really pinpoint the root cause. It's an older build, though good enough to play games such as Destiny 2 or the recently launched Black Ops 4 at almost max details in 4K; this of course after buying the 1070 GTX...