Please try the following to resolve this issue.
1. Check inside the dirt bin area for an on/off switch and make sure it is in the "on" (down) position
2. Soft reset Neato while still on the base by holding down the Start/Home button for 20 seconds.
3. Hard reset the Neato by unplugging one battery or turning off the power switch for 3-5 minutes.
4. When the Neato powers back on, check the LCD screen to see if it is working correctly. If the screen comes back up, follow the steps to calibrate the battery by fully charging and running three complete charge and discharge cycles.