I have owned my Garmin for years but one day the screen froze.  The watch only showed date and time but both failed to advance.  I went to the Internet to find a solution.  Each solution given required different buttons to be pressed at the same time.  Nothing worked.  Out of desperation I put the device back on the charger and started to press different button combinations.  What worked for me was to press all four buttons at the same time while it was being charged.  The frozen date time disappeared and “Garmin” splashed on the screen followed by the battery charge image.