Light, screen don't work, impossible to connect to phone

  1. Since yesterday, impossible to light the watch lamp. The touch screen does not work either. I can't even activate the 'touch' 'function in the settings. It is rated as Disabled. I reset my watch several times and nothing to do with it. Sometimes the lamp works and the screen too but it does not work again a few minutes later. In addition, the watch cannot be connected to Garmin Connect. I did not find anything about this on the forum .... Thanks in advance to all