Most new laptops nowadays do not have removable batteries, so when your laptop will not turn on previously disconnecting the power and removing the battery would reset the laptop and enable you to turn it back on.
With the new built-in batteries on new laptops you are unable to perform this method.
However there is a way of doing a reset by following the below.
- Remove all external devices (USB, Screen, power cord etc)
- Then press and hold the power button for 15 seconds
- Release the power button and hold again for 15 seconds, if your laptop does not turn on release the power button and quick 1 second press to turn it on.
If the above does not work then some Ultra books do have a reset pin hole on them in which you can push a paper clip into the hole to reset (they are sometimes located on the bottom of the laptop). But if your cannot find this or are unsure check with your manufacturers website.