New to B&O world and was really excited when I recently bought a Beomaster 901 with Beovox 1702 speakers and a Beogram 1202 all very dirty and in need of a super clean. That would all be be quite straight forward but sadly the RIGHT speaker input on the Beomaster is faulty. I could really do with some suggestions as to the problem. 

I have tried both speakers in the socket and I have also tried the tuner in case it was a damaged pin on the Phono plug which was at fault but not the case! The tuner works fine but only through the left speaker. The 2 wires for the right speaker socket seem to be well soldered and there is no crackle when moved. These wires, one green and one blue and white stripe - the green goes to the headphone socket and the blue disapears off under the circuit board, there's a lot of dust !!! 

There is sound from the right speaker socket but is is very faint and broken. There doesn't seem to be an obvious signs of a loose connection so I am completely stuck... any thoughts or help would be much appreciated.

I have a very nice cuircuit diagram that I found under the top of the Beomaster but hey... I'm no engineer!

Thanks

James

Welcome to the forum, most likely you may have bad capisitors and trimmers in the output stage, but also bad connections can cause this, as you I'm a happy amateur, here is what I did with my 901,

Before starting changing anything check the 32 volt supply voltage and the no load  current, how to should be on the diagram you found inside but take care not to shortcut anything, I did and that cost me more work than the normal cap and trimmer renewal.

Also before starting check 2R139/140 and 2R188/189 to se if they are 820 Ohm or 560/270 Ohm, in my 901 they are 560/270 and in most diagrams hey are 820.

Good luck and come back for help or with a succes report, recommend a cap and lamp kit from Martin (Dillen on the forum).

Thanks for the Welcome.

I saw your 901 post on here before I joined and it's really inspiring!! I have to say I really am an amateur so talking about trimmers and capsitors really goes over my head, not sure I would know where to start. The annoying thing is that is it such a lovely looking thing and the turntable I have adjusted and cleaned and even with one speaker working sounds great.

I don't think I have the basic knowlege to carry out a repair without blowing up a small part of England! The other thing is getting parts. It would be good to get the bulbs replaced to as they don't work either.

I am up for having ago but it would be like air traffic control talking down an aircraft flown by a passenger! If that makes sense.

James

In that case its better to find someone to do the repair, the parts you will need you can get from Martin (Dillen) he provides a set of capasitors trimmers and lamps that fits, with clear instructions how to change it.

If you cant solder or never soldered and dont know anything about electronics, dont start with the 901.

If you let it play as it is, the problems will get worse, for your speakers i recommend to change electrolitic capasitors as well, they are old and dry, your speakers will play but not as good as they can.

But dont give up, its a very nice reciever and it is worth saving, after a good repair it will play again for years, better than a lot of recievers you can buy today.

I agree, I think it's lovely and well worth the time spending on it. I shall see if I can find someone local to help me with it.

are there replcements for the electrolitic capasitors? I guess I should contact Martin?

I'll post some pictures of it all as it is.... 

Thnaks again for your help and advice.

Thats the spirit, and we love pics, before and after

I have been trying to locate someone who can help me with this ... local to me.. but really struggling. Is there anyone in Northamptonshire or surrounding counties handy with a soldering iron? :) 

I wanted to put some pictures of my B&O system up to but can't sem to load them .. is there a knack to this?

musicaltinkerer:

I wanted to put some pictures of my B&O system up to but can't sem to load them .. is there a knack to this?

 Pics Here, and wait for answers, someone in the UK will come up with something, meanwhile study this

And welcome to the Beoworld magic, beware of BeoVirus

Haha you are a wealth of knowledge Søren, thanks again. And your post on the 901 rebuild has been my bed time reading!

I am actually a photographer so I do appologise for the picture quality, I'm having the night off ! anyway here are some and I'll add some more.

Beautiful Items, as of the photos, field deapth or shutter time

Indeed, I just love the design and even the aerials make me smile, can't wait to get it all working...  photos are at 1.8 and at a snails pace! 

I did notice on the back of yours there are 4 speaker inputs?

I forgot all about photo, didn't use my Nikon for years, today its point and shoot with a friggin Sony.

Did you know that the rabbit ear antenna is worth more than the BM 901

And yes I have 4 speakers connects, which type and serial number do you have ??

Yes, the first 901's had different power transistors and 2 speaker outputs only.

The later ones had 4. Don't know the serial# on change.

  Gunther

HI.. just taken a picture of the back for you... I guess mine is an early one?

James