First, try completely unplugging the dryer for 5 minutes and then plug it back it. This may reset a frozen electronic control board in the dryer. A control board can sometimes freeze up if it encounters a power surge or glitch through the electrical lines during a power outage. If this reset the control board then the dryer may start working properly.
If the dryer still won't respond then you could have a component failure in the dryer.
I provided extensive technical information about this HE3 dryer in the images below. This information may help you diagnose the cause of your failure. The first step in diagnosis would be to try and place the control in the diagnostic test mode as shown in the first image below. In the diagnostic test mode you can check the door switch. If the door switch is okay then you can continue with the other tests in the second column under troubleshooting. Conducting the motor test may reveal the cause of your problem. NOTE: This information is intended for technicians. Follow electrical safety guidelines when using this information.
Unplug the dryer
to disconnect electrical power before accessing internal components. Internal metal edges in the dryer can be sharp. Protective gloves are recommended.
The technical information shown below can be overwhelming to some people. This is especially true if you do not have a technical background or experience. If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services