I have a BeoMaster2000 (Type 291x), a BeoGram2000 and a BeoCord2000. I recently unboxed it after being in storage for a few years and it worked and sounded great for about 15 minutes and then the BeoMaster just died. I just replaced the only fuse I could see (4A/250Volt) but still nothing. Any ideas? Any recommendations on authorized service centers