Garmin fenix 6 select button not working and screen fading

Hello 5905146

I am sorry to hear you are having trouble with the watch. There are some initial troubleshooting steps I would recommend. 

For the button concern:

• Ensure the watch is on the latest SW version using Garmin Express
• Wash the buttons: 
  1. Submerge the watch in warm/clean water for 10 minutes.
  2. Remove the watch from the water
  3. Press the buttons repeatedly. 

For the display concern, I would recommend a full factory reset with these steps: 

If this issue continues, I would recommend contacting Garmin Product Support.