unlock code mercedes audio 10

[williama]

I disconnected the battery and can't find the radio code. I have a Mercedes audio 10 cassette with 10 cd changer in the boot. It is a Becker be3100 with serial number 12838714. I have tried a number of unlock websites and they all provide a code with numbers greater than 4. The code is entered via the pre-set buttons and this radio type has 4, therefore any number above 4 can't be entered. I have tried Mercedes and their database records my car shipped with an audio 10 cd player and I imagine the first owner had this swapped for a cassette with cd changer and they (Mercedes) can't help. At least two sites and a software programme provide 21115 as the code but I can't find a method of entering 5.
The audio 10 cd device has code entered via volume nob but not on the cassette type.
Can anyone help, Williama

[_Franky_]

I disconnected the battery and can't find the radio code. I have a Mercedes audio 10 cassette with 10 cd changer in the boot. It is a Becker be3100 with serial number 12838714. I have tried a number of unlock websites and they all provide a code with numbers greater than 4. The code is entered via the pre-set buttons and this radio type has 4, therefore any number above 4 can't be entered. I have tried Mercedes and their database records my car shipped with an audio 10 cd player and I imagine the first owner had this swapped for a cassette with cd changer and they (Mercedes) can't help. At least two sites and a software programme provide 21115 as the code but I can't find a method of entering 5.
The audio 10 cd device has code entered via volume nob but not on the cassette type.
Can anyone help, Williama

correct is 42111 ...