I've built my PC in June and it's been working fine. As of two days ago however it wouldn't turn on anymore, but when I plugged it out, let it sit for a few minutes and plugged back in it was fine. Yesterday I went through troubleshooting and tried to put the gpu in different pcie slot, booting bare minimum and resetting bios which eventually worked. Today however I can't even get it to boot at all anymore. Tried reseating ram, using one stick, disconnecting peripherals, taking out cmos battery and shorting front IO connectors, leaving out gpu, using different pcie slot for gpu, taking out SSD but nothing has worked so far.
Specs list:
Case Coolermaster H500
MOBO ASRock B365 Phantom gaming 4
CPU i5 9400f
GPU Rtx 2070
PSU Coolermaster Mwe 650 gold (modular)
A Seagate HDD (ST2000DM008) and a corsair nvme (m.2) SSD (MP510)