Rescue guide for microcontroller ATSAMD21G18A

If you have a board that can't load the sketch then try to follow these steps: 
- Connect the board to PC; 
- Open the Arduino IDE; 
- Select your board from Tools>Boards menu; 
- Select your device from Tools>Ports menu (if it appears in Arduino IDE otherwise continue to follow the below steps); 
- Choose the blink sketch from File>Examples>Basics>Blink menu; 
- Push the Upload button; 
- Look the dashboard down on IDE and push one time the "Reset" button ( MCU-RST button for the Arduino Tian) when appears the PORTS list on dashboard. 
Rescue the microcontroller 
Note: 
This guide can be to use only the board with microcontroller ATSAMD21G18A: