[SOLVED] System will not stop rebooting - not sure what to do

May 17, 2021

I built my own PC back in 2013 and it has been running fine since. Recently I came home from college and fired her up only for it to reboot nearly immediately. It now continually reboots rendering it unusable. I have done some thorough research but cannot figure out the problem.

So far I have done the paperclip test to the PSU and the PSU fan did spin. I updated all my windows drivers and OS but the computer still continually reboots. I booted into the BIOS and let it sit to see if windows was the problem but it would still shutdown and reboot from the BIOS. I've also tried clearing CMOS but that didnt help. Next I took the rig apart and thoroughly dusted it out using compressed air. I even cleaned out the radiator to my Corsair h100i and reseated all components. This was the best result as I was able to use it for a full day with no restarts, but now it has gotten worse rebooting almost every 10 seconds after it powers on. I do not think this is an overheating problem because this computer used to handle high loads just fine. At this point I feel like I have done all I can and not sure what to do next. Please help!

CPU - Intel i7-4790k (not overclocked)
GPU - Nvidia GTX 970
RAM - 16GB G Skill Ripjaws DDR3
PSU - Antec HCG-620M
MOBO: MSI z97 Gaming 7