Lastest update seems to failed

[OnStandBy7]

Hi !

Today I've updated my phone (getting tired of the notification). I wasn't watching my phone so I didn't see if something went wrong, but it seems that the update passed.
New logo HTC displayed on boot and then... nothing.

I pressed the power button and it vibrated and displayed me the Fastboot mode. I shouldn't have any problem but when I press Volume -, it goes up and pressing Power button do the same... I can't press on Volume + beause it's brokken but the others buttons works fine...

The three first lines says :

" *** Software status: Official***
*** LOCKED***
*** S-ON ***

I can't do anything, not even shutting it down ! Not recognized by computer even with the drivers installed. I don't know what to do :/

I read that it may be caused by rooted or modified device but I never changed anything.

Have any clue on that issue ?

Thank you.

Edit : To make it simple : I'm looking for a way to select "Reboot to BootLoader" without using Volume and Power buttons. Thank you <3