Was this working prior to this or is this a new installation of the Nest?
How many wires are connected to the base and post pics.
What kind of heating system do you have? Forced air with ducts gas? Oil, Boiler with radiators/baseboard?
Check the Power info using the Nest on the base.
Tell us what the readings show for each.
This video explains how to do the test for the Nest Learning.
If the Vin is below 24v you might have a issue with the transformer in the system or blown fuse on the board in the system (they usually look like plug in car fuses). Or a loose R wire on the furnace.
Thanks for the update! I will be locking this thread in 24 hours. Please feel free to create a new thread should you have some more questions or concerns in the near future and we'll be more than glad to help.