XBOX One X Power Supply Replacement
If your XBOX One X is completely dead to the world, no power, no signs of life, then first, check your cable and the fuse in your mains plug.
If you know for a fact that your cable is working, then there is a strong chance your internal Power Supply Unit (PSU) has blown (70% chance).
Sometimes you may also get a flicker of life from your power button, maybe a second or so, and then switch off.
It could also be your On / Off Power button (20% chance). If so, check your on / off button. Can you hear the click of the switch when you press the on / off button? If you can't, then there's a strong chance its your Powerboard. Sometimes the surface mounted switch gets damaged, and you will have to replace the board. (Easy to do, see below)
See our How To Replace Your XBOX One X On / Off Switch Powerboard Video.
Otherwise, it is most likely your PSU.
We see it a lot, and it will involve buying a new PSU (Link Below)