Romeo board not recognized anymore

Development Tools IDE 1.x
1

Hi,
Please give me the hope that my Romeo (v2.0 [R3]) board is not dead. :cry:

It isn't recognized anymore : not present in /dev/. I tried from an Ubuntu and a Raspberry.
When I plug it (usb), ON and L leds light up (there is still life inside !) and the proc becomes hot quickly.
The reset button has no effect.
The last program pushed to the board was the second sample code of documentation : Romeo_V2-All_in_one_Controller__R3___SKU_DFR0225_-DFRobot.

Should I order a new one ?.. é_è

2

In found this from the "Loop-Back Test Instructions" topic :

"Force the processor to remain in reset by connecting a jumper from RESET to GND"
I'm sorry, I'm a newbie, but what is a jumper ?
I see the GND pin and the RESET button. I have to solder something ?

: (