Xbox One S will turn on for roughly 10 seconds then turn off again

Hi All

Started my xbox today and it wanted to do a system update. I said no and stay offline so I could play a quick game. Xbox then turned off and haven't been able to start it since. Looked at multiple solutions but could not fix it and I also replaced all cables.

Decided to open it and see if the fan was dirty. Turned it on while uncovered and noticed a few things.

• If the xbox was disconnected completely at the wall and then connected again, when I turned it on at the power button, I would get the beep, the fan would rotate a couple of times and then it would turn off. No lights at the power button.
• If I turned the Xbox on with the eject button, the power button would light up, fan would rotate a few times and then turn off.
• These factors were not always consistent and I've provided a video.
• https://youtu.be/wo8PYK-VW7Q

Does anyone have thoughts on the issue? Is it a faulty fan or something else since start up changes when completely disconnected from the power?

Cheers