Sometimes Lenovo laptops require a manual power cycle if they freeze up, meaning that the internal laptop battery needs to be unplugged for a few minutes before the laptop starts working again. 

Please follow the guide below:

1. Switch the laptop off and unplug the charger if it is plugged in.

2. Remove the external battery by sliding the release clips off to the side and sliding the battery outwards.

3. Unscrew all screws holding the back panel in place. Please see the attached photo which shows the location of all screws.

4. Lift up the bottom panel. If you cannot easily lift it up, then use a prying tool or any thin piece of plastic to release all the clips still holding it in place and remove the panel.

5. Disconnect the second battery from the motherboard. Please see the second attached photo which shows where the battery is plugged in. It is marked with a red square.

6. Wait approximately 15 minutes and reconnect the battery.

7. Reinstall the bottom panel and try starting the laptop up.