Few days ago bought BB black. Everything went till now. It been just powered up with usb cable, and I’ve been doing nothing with it. Then it accidentally switched off. Now it is not working at all, not even power led blinking. Disappointingly I don’t have 5v cable to power it up without pc, so I can’t check if it is a problem with usb or not. Can anyone please explain to me what is wrong with it and is it dead or not.