For anybody who has an Xbox One.....
As I repair computers and laptops my next door neightbour asked if I could look at his Xbox one.
It beeps and turns straight off once you press the power button.
Never fixed a console before.
I did a bit of internet research and come across a fan issue. When you power up the fan should start straight away.
On this system it didnt.
I got my vac out with the small tool attachment and ran it along the vent holes
I then got a hairdryer and set it to cool and full blow. Again I circled around the vent holes where the fan is.
Tried powering it up and yes it worked.
Apparantly when the fan gets full of dust (which they do) a sensor engages a power protection mode that shuts the xbox one off to protect it from overheating.
So there you have it, I hope this helps someone down the line and stops them paying for a repair they don't need