Before you remove the radio to see the label on the chassis, try the following to get the display to show the serial number:

1. With the unit OFF, press and hold the preset buttons 1 & 6 (you may need to try 2 & 6), then turn the unit on.

2. Let go of the preset buttons once the unit is powered up.

3. Look for the serial number beginning with V or M followed by six numbers. You may see various other numbers and letters, but you are looking for M/V******.