Xbox doesn't turn off - light blinking

I had this happen on my One X. I did some digging and discovered that a system will do this if it believes it is still too hot. You can sometimes fix it with a hard reboot.

Può capitare prova a lasciarla lampeggiare

[Translation-It can happen try to let it flash]

have you tried a reboot?

Or maybe a soft reset: https://support.xbox.com/help/hardware-network/console/reset-console-to-factory-defaults

Try this:

1. Power off your console, and then unplug the power cord to ensure that the console is completely powered off.

2. Wait 30 seconds, then plug the power cord back in.

3. Press and hold the BIND (controller sync button located on the left side of the console or bottom right if a one S or one X) and the EJECT button and then just press the Xbox button on the console once.

4. Continue holding the BIND and EJECT buttons for 10-15 seconds.

5. Listen for two “power-up” tones a couple of seconds apart. You can release the BIND and EJECT buttons after the second power-up tone.

6. The console should power up and take you directly to the Xbox Startup Troubleshooter.

7. To reset your console from the Xbox Startup Troubleshooter, use the D-pad and A button on your controller to select Reset this Xbox.

9. When prompted, select Keep games and apps. This option will reset the OS and delete all potentially corrupted data without deleting your games or apps.

If the console is shut down and the power light "pulsates", the console is doing some background "cleaning up". For example uploading savegames to the cloud, or finishing a system update.

Just recently, the May Update was released to the general public, and it might be, if your console is in power saving mode instead of Instant On mode, that the console is busy applying the update during shutting down.

Let the console run for at least 30 Minutes (depending on your Internet speed), and check if the console is still running after that time.