Merci, j'ai réussi à la redémarrer en passant par le mode recovery.
Manip à faire pour ceux qui en ont besoin :
Press and hold the power button until your tablet is off, then try to turn it on again and wait for about 5 or 7 minutes, if that doesn't work, let's have fun:
1 -Turn off the tablet by pressing and holding the power button until it power off.
2 - Press the power button and immediately press the volume down (Keep pressing the vol down button and release the power) If that combination doesn't work, do 1, and then press and hold power button + vol down.
3 - Now you're on bootloader.
4 - With vol- or vol+ navigate into the menu; select "Recovery mode" by confirming with the power button (You'll be prompted with the nvidia logo again and it will stay like that for 20 seconds aprox.)
5 - Now you'll see the little green android dead with a red signal.
6 - Press Power button and Vol+ at the same time in order to get into recovery.
7 - As above, use the vol+ or vol- to navigate, then whipe the cahe and after that, wipe the data (Factory reset)
8 - After that, select the "reboot system now" option.
If everything went fine, you should bne able to boot into your tablet, don't rush, after the factory reset it will take a moment to boot up, it will be "stuck" at the nvidia logo but not for one hour.