my levoit air purifier won't turn on, the display is completely dead, what's wrong with it?

It's not getting power. Check the outlet and the adapter first.

1. Plug the air purifier into a different wall outlet.
2. Inspect the power adapter and its cord for any damage. If you see cuts, frays, or exposed wire, stop using it immediately. That's a fire hazard.
3. Make sure the power adapter is firmly inserted into the back of the purifier.

If that didn't work, the adapter itself may have failed. It needs the specific 24V 1.5A adapter that came with the unit. Using a different one can damage it.

Heads up: If the adapter is damaged, contact Levoit Customer Support. Don't try to repair the cord or use a generic replacement.