Question EZ Debug CPU light stays on plus BIOS randomly reboots

Nov 24, 2021
Hi all, I've been saving up and have recently built a pc from scratch. However, as soon as the system is powered on the CPU light on the EZ Debug area remains on and there is no display. In attempts to resolve this I have refitted the RAM and CPU to no success. I have also tried using the update BIOS button on my motherboard to update it to the latest version. This didn't seem to work at first but after some fiddling around with cables and USB drives I managed to get the BIOS updated. However the CPU light still remained on. I finally managed to get the system to post by unplugging the graphics card and later plugging it back in, with the system off. But now I have ran into a new problem where the BIOS will just reboot randomly. It seems as if moving the mouse and interacting with it seems to trigger the reboots, but it can occur without touching the system. I have managed to get as far as the Windows terms and conditions before the system just rebooting randomly.
I have just at this moment tried turning on the system again and now it won't post and the CPU light is back on again. :( Does anyone have any ideas?

MSI B550M PRO VDH Motherboard
Crucial Ballistix RAM DDR4 3600MHz 2x8gb
Corsair CX550M
AMD Ryzen 5 5600G
Gigabyte GeForce GTX 1660 Super OC 6G