Join Date: Jun 2011
Location: Albuquerque, NM
You could try this:
nuvi 37xx series hard reset:
1. Power off the unit (press/hold the power button for ~7 seconds)
2. Power on the unit
3. When the Garmin copyright screen is displayed, press & hold the bottom-right corner of the screen
4. Release the screen when "Do you really want to erase all user data?" appears
5. Touch "Yes"
1. With the unit powered on at the map screen, press the bottom-right "Speed" field which will take you to the Trip Computer page
2. Press/hold the area just above the numerical speed on the round speedometer dial (where the compass heading is displayed when moving)
3. After pressing this spot for ~7 seconds, you will enter diagnostics mode
4. Select the first option displayed "Clear all user data", then follow the prompts
Reset all your location settings and user preferences. Also restore your favorites using the method outlined at the beginning of this post.
If possible after the hard reset (all units), let the unit sit outdoors in the open for about 30 minutes or so to let the unit re-acquire satellite almanac data.
At least you will get a functioning unit back and can investigate after that.