So i just got a brand new mavic pro but i have a problem with my controller:

Bassicly when there is no charger cable connected its completely dead. Can't even turn it on with the cable plugged in as seen in the video.

Anyone that can help?

I havent seen that before but it looks like a bad battery to me and probably has to be replaced. Is it still under warranty?

Hi, we do apologize for the inconvenience. We would recommend contacting our support or the re-seller of the drone for possible replacement. You may reach our support using the link below. Again, we do apologize for the troubles that it caused. Thank you for understanding.

www.dji.com/support

Battery failure by the look of it

I'd say the battery looks ok as the display is showing 100% when the USB cable is plugged in - the problem seems to be the On/Off switch. After leaving the controller to one side for a day - when you plug the cable back in does it show 'Charging' with the percentage (something less than 100%)? That would indicated that battery is functional and discharging as one would expect. By the way when the USB cable is plugged in - pressing the On/Off button should have no effect (bleep sound or display going on or off).

Never had that.
I would say you need to contact support!