B&O radiogram repair, Glasgow

[Jfdglasgow]

Hello 

My wife and I have just inherited a brilliant Bang and Olufsen Beomaster 900 RG from a family member. The radiogram is working and in really good condition but there is no sound coming from the speakers. 

We live in Glasgow and I was wondering if anyone knew of anyone who could repair it or help? It’s such a beautiful piece of furniture/ record player it would great if we could have it working properly, but appreciate it’s more of specialist item to repair . 

Hope this is the right forum for this, apologies if I have got this wrong. 

Many thanks 

Joe

[Murphyv310]

Hi Joe
I'm in Kilmarnock and used to be a B&O dealer, unfortunately I'm retired and no longer do repairs. There used to be a B&O dealer in Milngavie who also did service. Have a look online or the Yellow pages and see if they are still trading.
Don't expect a cheap repair for B&O an estimate or deposit could set you back at least £100.
Good luck

Edit
Specific spares for these sets are only available from B&O I'd not allow anyone near it if not fully familiar with B&O

[Refugee]

Is that not one of those sets with four speaker sockets and a switch to select them?
The last time I spotted one the switch was marked A/B.

[Murphyv310]

No Ref.
These are quite old from the 70s, the amp gave trouble I'm them, DC coupled from memory and usually needed a blanket repair. May of course not be that though.

[Jfdglasgow]

Hi, thanks Trevor for your reply and pointing me in that direction. Unfortunately they are no longer open in Milngavie. I’ll keep looking, would just be great to have it fully working if possible.

Thanks for your help

[Mike Watterson]

Seems to be two versions sold from 1968.
The stereo decoder was an option. A 3rd party modern IC will work. You can get a SMD to DIL converter and only a few parts are needed.

https://www.radiomuseum.org/r/bang_beoma..._2250.html
https://www.radiomuseum.org/r/bang_beoma..._luxe.html

I'd say easier fixed than some of the B&O portable radios.

Same radio chassis (approximately) as this https://www.radiomuseum.org/r/bang_beoma...0k900.html
and
https://www.radiomuseum.org/r/bang_beomaster_900m.html

Germanium audio amp and output transistors:
AC126 AC128 AC132 AD139 AC127

[Jfdglasgow]

Hi Mike,thanks yes it’s the De Luxe model. The radio it’s self is getting power as is the record player, it’s just not coming out of the speakers so may be the audio amp/ output transistor.

[Jfdglasgow]

Would it be a case of looking into replacing the transistors?

[Murphyv310]

I'd not personally assume it's the output transistors, it could be a simple issue, even power supply.
All my B&O Manuals went to the tip when they pulled the plug on us as we had to spend £250,000 per annum, not possible when you are an appointed service dealer and we were not in the position to open a retail outlet.
If you really get stuck I'd look at it but it would need to dropped off and collected plus I'm going for surgery on the 9th January.

[Mike Watterson]

I agree with Trevor. Make zero assumptions. Approx order to check. 5 & 6 could be swapped.
1) Check speaker continuity as the connection to voice coil can corrode (more likely than overload).
2) Check speakers actually connected (any switch on external speaker sockets or mute or whatever)
3) Check PSU quickly.
1, 2 or 3 is the most likely.
4) Quickly check the output voltage at amps.
5) See does record-player or radio feed tape socket. Record player cartridges fail.
6) Add input signal to tape socket and thus verify if main amp is working, if not, then see where signal fails. Did 1 to 4 really pass?

Can be a dried out electrolytic or a locfit type transistor if used (replace with similar TO92, they all have TO92 versions) rather than output transistors. Or the bias can be faulty if there is a pot.