Canon 7D won't turn on - battery icon flashing empty. please help

On the mini lcd screen

is an the empty battery icon that keeps on blinking even if its a fully charged battery

and even if the camera is switched off, that icon still blinks.

There are NO error messages displayed.

Tried to do something about it like turning it on and off, changing the

battery and trying another fully charged one, i even try to use another CF .

I’ve also checked the loose screw at bottom but the screw is in place. I’ve changed the lithium battery. I’ve tried 3 different LP-E6 batteries. I’ve tried to reset the electronic by pressing the shutter and the video buttons without batteries…nothing! the empty battery icon is still blinking and the camera won’t turn on! any suggestion? I live in a small caribbean island and sending the camera to canon is not an option…Thanks