PC not working

[Scintillon]

So about two weeks ago I was watching youtube and suddenly my screen froze and audio shut off and then my computer shut down completely. Upon attempting to turn the system on it powers up and then immediately shuts down and keeps doing that in 2 - 3 second intervals in an endless cycle.

I went to Tom's Hardware's guide and followed the steps there, removing all the RAM completely, booting with no RAM and switching the order of the RAM, didn't work. Tried switching out the power supply and the computer ran for about 3 hours and then shut off and started the turn on turn off cycle all over again. All components accept for the power supply and graphics card are 6 years old now so I'm wondering if the motherboard went bad.

Went to PC Part Picker and the only issue it says is my case has USB 3.0 but the motherboard doesn't support USB 3.0 but I'm not convinced that is the problem since it ran for 6 years no problem. I'd like a second opinion on this or if anyone else has had the same sort of problem and fixed it I would love to know how.

My PC Build on PC Part Picker: https://pcpartpicker.com/list/zYHFNN

If you need me to add more info to that build let me know.

[Saltymuffingaming]

Does it POST at all? Do you see any logos pop up or does it just power on and then shut off? If no POST then its probably a motherboard issue.

If the computer gives you a beep error code when you attempt to boot up with no RAM at all installed, its likely the motherboard itself. 6 years is a good run for most hardware to be honest.