Question PC keeps fully crashing without any error or warning

Jan 19, 2020
so here are the specs(ask me stuff because I dont really know much and probably have missed stuff i should have written)
Operating system: Windows 10 pro 64bit (used to crash on windows 7 so i switched to 10 but nothing changed)
processor:amd Fx(tm)-8120 eight core processor ~3.1Ghz
Memory:8192MB Ram
Gpu:amd radeon r9 380 series
System manufacturer: Gigabyte Technology Co
Psu: VS650 80+ 650 watt

My PC is approximately 3 years old. It started to crash like a year ago then after a month or so it just stopped crashing. now after like 3 years of gaming it started to crash again. My temperatures are not high i mostly set my fan speed around 65%-75% speed and its mostly nothing more than 45 or 55 degrees celsius. I used the amd cleanup utility for drivers many times and tried other driver versions but none of them helped so rn im using the latest recommended version(19.12.2). I tried cleaning my whole case all the fans of everything like psu and stuff but didnt really change anything. Some time after my crashings i started underclocking my pc(well i only set power target to 80 and GPU clock to 780Mhz the default is 990). Even tho it helped me for a bit now it started to crash again. I dont crash at games like terraria but i cant even play destiny 2 i load in but as i try to walk around the pc just shuts down. But in games like payday 2 it doesnt crash most of the time but at some missions with too many things it just crashes.

Again ask me about any more info ill try to look them up and find them.