Most likely a power or connection issue. Check two things.
- Make sure the air fryer is plugged into a working outlet. The power cord is short; don't use an undersized extension cord.
- Push the basket securely into the air fryer until it clicks. It won't power on if the basket isn't fully seated.
If that didn't work: Unplug it and check the power cord for damage. If the cord is damaged, do not use the appliance. It must be replaced by Cosori or a qualified person to avoid a hazard. Contact Customer Support.
Heads up: If no buttons are pressed for 30 minutes, it shuts off automatically. You'll need to tap the power button again.