The power cord may not be connected. Make sure the power cord is connected to an electric outlet for 120V/60Hz.
The display may be off. To check the display, press the power button. When the display is on, it will light up. Select the desired function from the display.
The power may be off in your home. Confirm that your power is on. The Coway Tower will not work without electricity.
The front cover may be loose. Check that the cover is secure. The Coway Tower will not work unless the front cover is closed securely.