XBox One X (project scorpio) turns on then turns off

I am reviving the topic of a number of locked threads because I think it is relevant and previous threads did not satisfactorily identify the cause of the issue. I have a XBox One X (project scorpio) console that has worked flawlessly since day one. It is
in an actively cooled cabinet that is not over crowded and it has seen very light use. I am not a heavy gamer by far, in fact, I would say that I use other online and streaming services with the XBox just as much if not more than I use it for gaming. I have
a 5TB external hard drive connected to it on which I have all of my games. I also have a Kinect attached using the Kinect adapter for the One X. It is connected to a 55" Sony HD (not 4K) television.

Last night, I decided to get on GTA (the disk was already in the BD-Rom drive) so I launched it. It started to load but shortly after, the XBox just turned off. I just figured it had crashed so I tried to turn it back on and have not been able to get it
to come back up since. If I push the power button, the power light comes on and I get the startup tone like it is going to boot up, but a few seconds later it turns off, sometimes playing the shutdown tone but most of the time it just shuts off. I have tried
all of the usual troubleshooting steps outlined by Microsoft and others here. If I press the eject button, it will come on long enough to eject the disk and then turn off. I have disconnected all of the USB and video cables and tried powering it on but it
does the same thing. Obviously, it is out of warranty, even in my state where we have double the time warranty laws in place so sending it to Microsoft would cost $249. I do not wish to spend $249 on this console 5 months before the new Series X is scheduled
to be released, which I fully intend on purchasing.

So what I am looking for here, from those that have experienced this or that have more knowledge of these consoles than I have, is an answer to the cause of this issue. In my mind it is either the internal power supply or the hard drive. If it is the power
supply I can source a replacement and I can replace it myself. I am very good with hardware. I can also replace the hard drive if there is a method for doing that. The external hard drive appears to still come on so I am not thinking that is a factor in this
but let me know if it could be. Any help is appreciated. I also do not want to lose a lot of my XBox Live time so I am in a hurry to get this resolved.

:)