[SOLVED] i am completely baffled

[ItsmeDarcy]

I have a computer that refuses to cooperate with me.

Original specs:
MSI B450 Tomahawk MOBO
AMD Ryzen5 1600 CPU
EVGA 650w PSU
XFX rx580 8g GPU
64g Corsair rgb RAM

The paraphrased version..
While playing a game, computer just shuts off. Game is not very demanding and im like...thats weird, especially since my rgb ram is still flashing but fans are all dead. Power button/reset button does nothing, so i switch off the PSU, wait, and switch it on again. Power button works, PC is on for about 20 min and shuts down again, rgb ram still glowing. Only now, it will not turn on again.

So I replaced the PSU with an EVGA 850w.
Still dead.
I replace the MOBO with the Steel legend.
Still dead.
I replace the CPU with the ryzen 7 3600.
Still dead.

I ruled out GPU and RAM.
I just bought a new case, just in case the power button was shorting out...but i doubt it.

Here is the thing that gets me...if i switch on the PSU, the MOBO rgb's on the Steel legend glow and flash saying, "hey biatch, we have power!" So I hit the power button, the cpu fan kicks on and immediately off, the fan spins about 1/4 turn. (and rgb lights up for about 1/4 second), but only on the first button press. Anything after that, it just stays dead. Meanwhile the MOBO rgbs are still lit and flashing oh so pretty.

So...what the heck is going on?? I've already spent way too much money replacing parts.

 

[Ralston18]

Consider installing a new CMOS battery.

How did you apply the thermal paste and what paste did you use?

 

[faalin]

Since you have replaced everything i would have thought about, do you have the computer plugged into a power strip/battery backup unit?

Also have you tried moving the computer to another outlet that is not on the same circuit breaker you are currently using.