Xbox One Won't Fully Turn on. Instead Getting System Error

Several have indicated that the steps here
support.xbox.com/.../offline-system-update-diagnostic-tool have corrected this issue. Good Luck!

To make this happen like 80% less set your xbox ones power mode to Energy Saving, instead of instant-on. This will allow the system to fully shutdown when you turn the system off.

If the system is fully turning off i donno how to fix it. =/

If its just the games closing and returning you to the dashboard the Luckily you can actually fix that issue....

Goto Settings, then power options and change the power mode from Instant-On to Energy Saving and then turn off the system.

Reason why it works is when Instant-On is on its basically sends the system into a standby mode when you turn it off instead of fully shutting it down your console never fully gets to shut down and the xbox one never gets to boot up fresh. Energy Saving
mode will let the system fully turn off. When using energy saving mode the startup of the system can take like a min or so. Once your issue is fixed simply re-enable instant on and it should work like normal. Just repeat if you have the issue again. Or
you could just leace it on energy saving if you can stand the long startup screen. Its weird that the system has this issue, hope its fixable threw a update. =/

Set your xbox one's power mode to energy saving instead of the default instant on and it will allow the system to fully shut down when you turn off the system instead of staying in a standby based off state. This will let the ram boot up clean and wont
have this issue. You can reenable instant on mode once you reboot with energy saving mode. But ive found it best to atleast turn off ur xbox with energy saving on atleast once a week to let it do a full startup.

I'm having that problem also. My system was working great, but the power box kept turning off. Got a new power box last night, but now it won't fully turn on.