Beomaster 6000 4channel

23rd May 2014

The fault with this set was that only Tape 4 could be selected, all other modes resulted in an instant return to standby. Even in Tape 4 mode there was no sound, although all the volume and tone control functions operated normally. Assuming that all the supplies are present the voltage across 8R11 (100R) is a good place to start when problems are encountered in this area but it proved to be correct at just under 3V. The muting line should normally be at -5V but was found to be at nearly +10V – this explained the absence of sound. The source of the unwanted positive voltage was 8TR26 but the transistor itself was not faulty; instead 8C12 (47uF 63V) turned out to be leaky and this prevented 8TR26 from turning off fully after the initial reset pulse had been formed. Replacing this capacitor cured all the symptoms. [Beomaster 6000 4channel]