Sometimes, when you troubleshoot a MacBook, MacBook Pro or MacBook Air problem you need to turn it on without using the power button. Is it possible? Yes, it is!
In these laptops (unibody style) the power button is permanently attached to the keyboard. Basically, it’s a part of the keyboard as you can see on the following picture.
If the keyboard failed (let’s say you spilled liquid on it) and the power button stopped working there is a workaround for turning it on.
You cannot use this method to turn on your MBP on a daily basis but it is a good troubleshooting technique. It might help to figure our if the motherboard still works even though the computer doesn’t turn on when you push on the power button.
You can turn it on by shorting the power-on pads with a small flathead screwdriver for a couple of seconds. The power-on pads located on the motherboard. In order to access them you’ll have to remove the bottom cover and it’s very easy.