Lenovo 81nc advanced bios options
Accessing advanced BIOS menu
First using a needle or a toothpick click a button on the right side of the laptop (indicated by a bent arrow), this will start the machine up in BIOS selection menu where you choose the BIOS setup option.
Then, in the BIOS menu disable option to check laptop charge level while it is shut down. If not disabled it will interfere with key combination that has to be pressed while laptop is shut down. This can be turned back after the advanced BIOS menu is enabled.
After that "Exit saving changes" and shutdown.
I thought it was a joke at first but it really is true that a special combination of keys has to be pressed depending on the laptop model (while it is shut down).
For my laptop it is as follows:
1 2 3
F4 4 r f v F5 5 t g b F6 6 y h n