View source for Honda/1BU5/serial number

[[File:IMG 20200804 194645713.jpg|thumb|the 1BU5 displaying its serial number]]
'''To retrieve the serial number''': with ignition on and radio off, hold down the "1" and "6" keys simultaneously and then turn the radio on. The serial number will immediately appear on the radio's segmented LCD display.

There is a visual demonstration of this technique on a different model of player in [https://www.youtube.com/watch?v=LbSh-8TRf00 this video from 2014].