Airport Express Stopped Working

I have tried all the reset options,but it is still not detected by my airport extreme basestation and just flashes amber.

If you reset the AirPort back to factory default settings.......then it will not be detected by the AirPort Extreme.

If the AirPort Express is working correctly after the reset.....it must first be detected by the AirPort Utility setup "wizard" on your Mac......so you can set up the Express again to connect to the AirPort Extreme either by wireless or a wired Ethernet connection.

You get the setup "wizard" running by clicking on the WiFi menu on your Mac and looking for a listing of New AirPort Base Station. Just under that listing, click directly on AirPort Express and wizard will open up and guide you through.

Now, if you are saying that AirPort Express does not appear under New AirPort Base Station, and you have reset the Express a number of times.....then the Express is likely defective.

Try the iPhone or the iPad

Go to the Home screen on the iOS device

Tap on Settings

Tap on WiFi

Tap on AirPort Express under the heading of Set Up New AirPort Base Station

The wizard will guide you through. If you are still having difficulty, the Express is likely defective

Might you be running Sierra on the Mac? Lots of bugs in there, as well as El Capitan.

Power off everything on the network and then start up devices one at a time starting with the modem first to see if that might help.

Do you have an iPhone or iPad handy?

"Unknown" connection is one of the bugs in El Capitan, so you'll have to live with that.

Look to see if there is a setting for Status in the same small window with the "Unknown" connection info

If yes, click on the small amber dot there and another window will open up to explain more about the issue

What is the issue?

If Status does not appear, then I'm afraid we're stuck, and it's time to try a new Express.

Defective AirPort Express