No Led of the FMU lights up and the Pichawk heats

Hardware Pixhawk family
1

Hello?
I need some help, i was using my Pixhawk1 and when i plug the USB to use it, No Led of the FMU lights up and the Pichawk heats
any solutions ?
This is a picture of my issue

2

Plug in the switch and hold it down when you plug your pixhawk in.

Thanks, Grant.