Charing problem

A few factors to consider if you are encountering difficulties in getting your Garmin watch to charge: 

• Change the USB power source you typically use to try an alternative power source that what you have been using. We recommend connecting to a USB port on a home computer to determine if the watch is being read as a device drive as well, due to the computer providing more information to go off regarding the connection. 
• Once you connect the watch to an alternative USB charging source, if the device is not powering on...press and hold the middle button on the side of the watch and keep it held for 15 seconds > Then release the button > Disconnect and then reconnect the cable > You should then see the Garmin logo appear on the screen. 
• If the Garmin logo does not appear on the screen, check the end of the charging cable that connects to the back of the watch. Inside the connector, you should see four pins. All four of the pins should be the same color, shiny metallic, sticking out the same length, and equally spaced. None of the pins should look bent, pushed in more than the others, or different. If the cable does not look exactly as described, the cable will need to be replaced with a Garmin data cable at this point. 
• Users should also check the four metal dots on the charging contact on the back of the watch. All four of the dots should be identical, shiny, rounded and all the same color. None of the dots should appear a different color, corroded, dented in or different from the others.

The troubleshooting article also mentioned in the other comment from seilogramp is also a Garmin Support page resource that should also be reviewed if having issues as well.