Well done! It' a nice feeling when you finally succeed!

Yes, that looks better :-)

Have you got it up and running?

Chris

Well done, well done! 🙂 All you needed was a little incentive. You figured it out all by yourself, which is an essential learning step.

I wouldn't be too happy with the seller though. Unless the arm was given away to you of course!

Thanks Bo, Chris and Jacques.

Yes, Today is Ta-da!

No, I haven't got it up and running yet. Hope I will soon. Next step is to figure out how to draw these microscopic leads through the slide internals in a good manner. So I don't exactly feel any serious reason for arrogance right now. And about the seller I'm just gratefull that a tonearm existed for my table at all - as they are very hard to come by these days. And one can't hold it against the seller, I think,  that B&O, flimsy as it seems, changed the lay-out of the Bg4000 tonearm three times - after all this was their first tangential experiments and experiences.

The real problem was that I unfortunately didn't know this before now.

Time to proceed...I shall be reporting back as soon as it all plays...and in case of upcoming mysteries, earlier.

Thank you!

:)

Hi, so is there actually a problem with the wiring that stops you connecting your 'new' arm to it?

Chris

Hi Chris,

no I don't think there actually is. But since this is my first time doing this, I feel somewhat uncertain and I am planning everything carefully in detail. No stress. At the same time I am documenting each step I take in text and photography. Takes time too. But who knows, maybe it can lead to a tut some day. A tut for novices - written by one.

:)

As Henry Ford said, 'If it ain't bust don't fix it!' Or something like that.

i took one look at the wiring as I was going to do a complete swap, but thought, "On second thoughts, I think I'll leave it alone." :-)

Chris

I've had the Bg4000 up and running now. It played. But my left stereo-channel was silent. And still is.

The wiring became complicated because of the mix of tonearm-models. The donor arm contains only thin copper wire leads, without any color coding. And the receptor arm fragment is a model containing a small circuit on which the leads are soldered.  I did so following the diagram for another cartridge-type, trying to translate the diagram to the MMC4000-type. As there was no colored leads in the donor arm, I had to reconstruct the colors from the SM information. And I have been following Menahem's article on altering the wiring in a reversely/wrongly wired arm in a Bg4000 reconditioning.

I followed this diagrammatic sketch:

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- and more or less guessed that the wiring of the MMC4000 probably should be like my extra sketching. The small color picture at the right has been borrowed from Menahems article on this forum. I hope that's ok.

I have measured the whole thing and found that the white wire from the connector no3 which I see as analogue to L unfortunately has a short to chassis. And I can't find where it is. So the channel is silent. The right channel is working ok.

The muting relay is working physically but I have a little humming and no muting between start and when the stylus contacts the record. When the record is being played there is no humming - it sounds normal - but only in the right channel just now of course.

When measuring the leads I used a small piece of paper as insulation in the relay.

Any ideas for attacking  this problem will be very much appreciated.

:)

Had an idea that I would try to simplify the sketch of the Beogram 4000's tonearm wiring. To make things easier. This jigsaw puzzle is step one on that road:

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 Will this play?

:)

Yes, it plays.

Everything works fine now - the sketch works, I hope it can be of help for some other novice fighting a BG4000 tonearm problem.

Problem solved, case dismissed.

:)