Gears appear when the Nokia n800 is turned on.

Hi! If you mean Lumia800 mobile phone, you can press and hold down the volume down button and the power button at the same time 10 seconds to restart the mobile phone. If the same situation still exists, please forcibly reset the phone by:

1. Long press the power button to turn it off;

2. Press and hold the volume down button, power button and shoot button at the same time;

3. When the mobile phone vibrates, release the power button, but continue to hold down the volume down button and the shooting button until the mobile phone restarts.

Tips: This operation will delete all personal data in the mobile phone.