Turn on the dryer. Make sure the dryer door is shut tightly. Wait for the dryer to start. If the dryer does not start, press firmly along the edges of the door.
If the dryer fails to start or the door pops open and stops the dryer, open the dryer door. Look around the inside edge of the dryer door for the small lever. It will be on the inside edge opposite the side with the door hinges.
Inspect the lever and make sure it is free of lint and debris.
Inspect the slit on the inside edge of the dryer opening. This is where the lever connects to the door sensor. Ensure there is no lint or debris trapped in the slit.
Press gently into the slit with the tip of a flat-head screwdriver to unjam the plastic piece inside the slit.