I have a volume control problem on this machine but it should be fairly straightforward to fix.  The volume up works OK but there is no volume down response.  I downloaded the relevant service manual from the site and that is where the confusion starts.

The cover of the manual says "Beomaster 2400, Type 2901".  My machine is the Beomaster 2400-1 but it is also marked as a Type 2901.  However, it is clear that my circuit boards bear no resemblance to the ones in the manual.  I thought that the "Type number" related to a fixed configuration for any machine?  Can anyone help direct me to a correct copy of the circuit diagram for board 3?  I am assuming that small board still contains the volume control circuits even though it looks a lot more complex than the older 2400 board.

Any help or pointers in the right direction would be appreciated.

Geoff

Two different types of volume boards were used. The early type has 16 volume steps and one IC, the later type has 128 steps and (I think) three IC's. The type of board mounted is not related to the ...-2 extension.

Try looking at the last pages of the manual for any aftermarket changes and upgrades or check a Beomaster 1900 service manual, they are very similar.

Martin

Thanks Martin, at least I now understand where the second board fits in.  It certainly has 3 IC's as you mentioned.  So far, all of the diagrams in both the 1900 and 2400 manuals refer to the single IC board and they also provide a very good description of how it all works..  My old 1900 also has the simple board which is easy to work with and I am struggling to see any similarities between the two boards.  I'm afraid that I will have to wait until I can find that circuit diagram.

 Regards, Geoff