I recently built a PC comprising of Ryzen 3100, Gtx -1650 super, Asrock B450 Pro-F mobo, Cooler Master 550W PSU and 8 gigs of Hyper X ram. All Games run fine without any problem but the computer randomly shuts down when left idle. And during next bootup no error is shown by the computer. I'hv checked all the temperature and results are normal. Have installed all drivers and windows 10 updates and updated BIOS. I have to inform 2 things- Firstly, I'm still using a 2009 bought 320 gb SATA HDD( I'm planning a new SSD). Secondly, I'm using my computer without a cabinet( I'hv ordered one). Can anyone please help me? I wanna know the solution of my problem.