keyboard and mouse showing no lights

I got a computer from my brother that he didnt want because its not portable so I factory reset it, after it loaded all its stuff it asked me my region to help set up the computer and the mouse and keyboard didnt work like they werent plugged in! Brother says he doesnt know whats going on and it...

Hi, I have brought new system 3 days ago and assembled it my self. It started properly but after 2/3 hours its stoped working and showing no display. Configruration Ryzen 9 3900x MSI x570 a pro Gskill 16x2 ram 3200mhz NZXT krakken x62 Intel M.2 500gb ssd Corsair vs650 watt psu Old gpu amd...