Beomaster 3000-2

19th May 2009

This receiver would not stay on tune, the stations drifted erratically about and sometimes disappeared all together. At first the frequently troublesome selector switches were blamed but cleaning them made no difference. A meter showed that the tuning voltage was steady in any case so the tuner front-end was investigated. The tuner unit proved to be extremely sensitive to tapping about with an insulated tool so poor soldering between the case and PCB was first suspected. This proved not to be the cause, the real culprit being the oscillator trimmer (40). The screw was loose and making poor contact with the body of the component. On removing the complete trimmer from the board it was possible to unscrew the threaded part completely through the bottom, this revealed that the two sprung contact fingers inside had relaxed and become stuck in old grease, re-tensioning and cleaning restored stable operation once the trimmer had been refitted and realigned. [Beomaster 3000-2]