search on ebay.de, you will find a lot of audio repair kit's(great for diy), or just send your BM for repair; i did used an tda 7560 audio kit presoldered (brought from here:PSC-Audio | Module KIT | Module PsC-Audio | KIT127D - 4x34W (TDA7560), was about 19 euro shipping included) and, after about 3 labor hours BM was alive again, is not very complicated to do but you will need some electronic skills..

regards