Starts & Restarts - Repeats

I installed Linux Mint, and wiped out W10.

I restart the PC, and here is what happened:

It powers on (but the lights contained in the fans was not as bright as it usually is), and then shuts off immediately.

The thing is, it has happened even when I was running W10, but it has brighter fan lights, last a little bit longer (before shutting off) ~approximately 1-2 seconds. But, I had to keep hitting the power on button to start it.

And the cycle continues; it eventually starts (before Linux Mint).

As of now, it will turn, and then shuts off, repeatedly. I had to unplug the power cord or else it will keep turning on-shutting off on its on - non-stop.

Is this a PSU issue?