Why my device won't power on?

@jocamera not a lot of information here. You should at minimum tell us what you have tried. I suggest:

• charging the battery,
• replacing the battery,
• check the battery door to ensure it makes proper contact with the battery
• check battery contacts
• Disassemble the camera to the mother board and check for bad fuses or bad component on board

this guide will at least get you into the camera. Post some pictures of your mother board if you have to work on it so we can see what you see Ajout d'images à une question existante