Press and hold the Microphone off and Volume down buttons at the same time until the light ring turns orange (about 20 seconds). Then light ring turns blue.
Wait for the light ring to turn off and on again. ...
Open the Alexa app to connect your device to a Wi-Fi network and register it to your Amazon account.
Step 1. When you have to reset the echo dot, then first of all, press and hold the mute & volume down button at same time. Wait for 20-25 seconds until the light ring turns to orange.
Step 2. Leave the buttons and make sure the light turns to blue. If it doesn't then wait for 5-10 seconds.
Step 3. Now, wait until the light ring turns off and turns on once again. After a while, your device will show the light ring turns orange again. It means your device has turned into configuration mode.
Step 4. Finally, configure your device with Alexa and continue