If your Forerunner 35 is no longer powering on, give the following steps a try:

Confirm that your power/data cable is not damaged.
- Check the charging pins to ensure they are free of debris and not damaged.
Check the charging contact points on the back of the device for dirt or debris.
- Use a pencil eraser or a cotton swab dipped in rubbing alcohol to clean them.
Make sure the watch is not frozen or locked up
- While the watch is plugged into external power, press and hold the power button (left button) for up to 30 seconds. If the watch beeps with a screen flash you can release the power button and try turning the watch on again.

My watch will still not turn on.

If you continue to have an issue the watch will need to be replaced. You can request for an exchange using the following tool: Garmin's Online Exchange for the Forerunner 35