Check the power connection first. Make sure the unit is plugged into a working outlet and the cord is fully seated.
Press the ON-OFF button on the control panel. The LED light in that button should illuminate. If it doesn't, try a different outlet. If the LED lights but the fan doesn't run, the speed selector bar might be stuck. Slide it to select a speed setting (LOW, medium, or Turbo).
If that didn't work, the internal overload protector may have tripped. Unplug the unit from the wall for 30 minutes, then plug it back in and try again. If it still won't power on, the control panel or internal wiring is likely faulty.
Heads up: Always place the purifier on a firm, level surface. Using an extension cord or power strip can sometimes cause issues.