Please check the following -
- Check the power plug to see if it is properly plugged at the power socket.
- See if the DC connector is properly plugged in the air purifier’s DC jack located under the air purifier.
- Check the reusable filter to see if it is properly installed in the air purifier. The reusable filter should be at the same level as the front panel if it is properly installed.
- If you have removed the front and/or back cover for cleaning, check if they are properly installed all the way up and locked.
If you hear the fan is ON, but the LCD screen doesn't light up. It may be operating in "Sleep mode". If so, just press the LCD button once, the unit should be exiting Sleep mode and the LCD will turn back on.