Bang & Olufsen Amplifier Repairs
Bang & Olufsen Beomaster 1700
This had only the LHS speakers working, a major blow up of the RHS power amp had took place. Suspect the quiescent preset had gone open circuit taking out most of the bits in the power amp (there are not that many to start with) Darlington's, diodes and four of the five transistors and emitter resistors.
Bang & Olufsen Beocenter 2300
This one was dead, the 2A fuse had blown in the 15V supply due to a faulty bridge rectifier.
Bang & Olufsen Beomaster 6000
This was blowing the 160mA fuse to the smaller transformer, the 3300µF 16V RDE capacitor was short circuit.
Bang & Olufsen 3000
This looked as if it was not powered up, first off the power switch( with 'off' over it) is 'on' when it's up indicating 'off', I'm confused already. The problem turned out to be the switch bank, all the lever switches are on an interlinked assembly and either the lubricant had dried out (it's from 1969), or the contacts were corroded. A couple of soaks in WD40 equivalent was needed along the whole length, the symptom was FM drifting through the stations (its varicap-voltage tuned) and left\right channels not working, a constant operation of all the switches for a length of time (too long) eventually got them working again.