Are you able to hold the power button to shut it down? What happens when your restart/turn it back on?
Do you see anything on the screen like the logo? Do you hear the fan running?
I would try the reset hole on the bottom of the laptop.
== When to use the reset hole ==
The reset hole can be used for the following situations:
* A unit will not power on, either on battery or AC power.
* A unit will not power down using either the operating system or the power switch.
* A unit will not resume from standby
The pinhole reset button is located on the bottom part of the laptop.
See page 21:
https://download.lenovo.com/pccbbs/mobiles_pdf/a485_ug_en.pdf