Trying to reconnect my AirPort Extreme model A1408 - Flashing Amber light

Then unfortunately, you will need reset / erase the settings on the AirPort Extreme and then set it up again.

We assume that the AirPort Extreme is connected to your modem, correct?

Power up the AirPort Extreme and let it run for a full minute

Hold in the reset button on the back of the AirPort Extreme for 7-8 seconds and release

Allow a full minute for the AirPort Extreme to restart

On your Mac.....Open AirPort Utility

Click the Other WiFi Devices Button

Click on AirPort Extreme xxxxx

A window will open with the correct setup for the AirPort. Follow the prompts to enter a name for the Wireless network, base station and password.

The MacBook Pro should be able to connect to the Wi-Fi network signal that the AirPort Extreme is producing.

Can it?

If yes, should be able to access the settings on the AirPort Extreme using AirPort Utility if needed.

(Finder > Applications > Utilities > AirPort Utility).

Please report on your progress.

Nice work!