a. Press and hold the power button for 2 secs to turn on the bark collar. ( Note: If there is no operation button for 10 seconds, the device will automatically lock, press and hold the power button for 2 secs to unlock.) b. Whether the collar indicator shows charging after plugging in the charger. (The red light means it is charging) c. If no charging is displayed and the charging cord is checked without damage, it means that there is a problem with the collar.