dead nest thermostat, about two years old, only a red light flashes at the top, any suggestions?

[rhadow]

Perhaps your Nest thermostat is a different generation from mine ("red light").  Have you tried changing the AAA batteries?

[Tommarchetti]

Were are the batteries located, I removed the back of the selector ring and they are not there.

[Jeff]

Hi, everyone. 
In an effort to keep content fresh on the forums here and prioritize current issues, I'm going to go ahead and close up this thread. If you have any outstanding issues from this post or any other problems, please feel free to open up a new discussion.
Thanks,
- Jeff