After a long enough work on the laptop, it sometimes does not turn off completely. Namely: the POWER button remains on, the power indicator remains on (you can see on the screen), sometimes you can hear the activation of cooling. 
Notebook model: Dell vostro 5470 Windows 10 Pro 64 (by the way, these problems were noticed after upgrading from 8.1 to 10) All drivers have been updated.