AirTag not working

Welcome to the Apple Support Communities.

See: Set up your AirTag using your iPhone, iPad, or iPod touch - Apple Support, specifically this section:

If you can't set up your AirTag

Make sure that your device is ready for setup.

If the setup animation disappeared, press the side button or Sleep/Wake button on your iPhone to put your device to sleep. Then wake and unlock your iPhone. Wait up to 15 seconds, and the animation should reappear. 

If you have multiple AirTags to set up, make sure that only one is near your device at one time.

Remove and then replace the battery in your AirTag.* 

If your AirTag still won't connect to your device, reset your AirTag. 

Learn what to do if you see a message that says the AirTag is connected to another Apple ID.

Jack

I’ve got the same issue & I tried to do the reset but I don’t even hear a sound when trying to reset.

cover is off and pressing battery but nothing.

it won’t find it when looking with my phone.

it worked initially for a week but now nothing.

thanks