If you have already attempted the steps in Computer will not power on: First thing to try and your computer is still not starting, the following steps may work if you have a Lenovo X1 computer. 

Instructions to use Lenovo X1 reset button

Create a step-by-step guide

Step 1: Remove computer from power supply

• Remove computer from docking station and make sure it is not connected to any power supply.

Step 2: Find a paper clip (or something equally small (I've used a thumb tack).

• Find a paper clip (or something equally small (I've used a thumb tack).

Step 3: Flip the laptop over

• Flip the computer over so you are looking at the bottom and locate the small hole.

Step 4: Place paper clip in small hole and hold for 30 seconds

• Place paper clip in hole (you should feel a slight click) hold this down for 30 second

Step 5: Connect computer to power supply

• Connect computer to power supply (or dock with power supply) and attempt to power on.