[Dillen]

Check the DC voltage to the motor with a scope. Look for correct voltage and amount of ripple.

Martin

[Dillen]

Do you have continuity (ohmic resistance) from pin 1 to 3 (speaker disconnected from mains)?

Martin

[Dillen]

Missing solder pad at the transformer pin below number 1 in your photo?

Martin

[Dillen]

I understand, but a modern motor won’t last longer than a restored original.

The original motors can be described in two words; Ro Bust.
Bearings run out of oil or dry out. All sinter bearings can and will eventually do that.
A solution to this is readily available for the Beograms in that you can re-infuse
the bearings if they are still structurally good (only few are by now) or you can replace them altogether. They are fairly inexpensive, they come pre-oiled ready to fit, and no
other parts of the motor will be worn or bad in any way (unless mistreated or stored badly,
in which case a lot of others things would presumably need attention too).

A modern motor can rarely be serviced. There is not a lot of chance that somebody will reproduce correct bearings, not now and not in fourty years, and most modern motors have wound anchors which in turn means brushes that will wear out and/or break.
The original B&O AC motors are of the one-phase “short-circuit” anchor type.
They have no brushes. Only stationary windings.
They are wonderful motors. Modern stuff is not always better.

Regarding Beolab 8000 etc. active speaker standby transformers. Original transformers
may not be available anymore, but I have managed to repair quite a few speakers
using alternative transformers, and I know so have others.
It’s not end of the life for a speaker if the standby transformer dies.

The VX5500 breaks a loading gear.
That’s a well-known, almost standard, fault in these machines and, even if I rarely do
TVs and VCRs, I’ve replaced a handful or two of these gears in my time. That’s as common as this is.
The part is (or at least was) available from the drives original manufacturer (Hitachi, if I remember correctly – it has been some time since my last VHS), from where I’ve
bought a few and I wouldn’t be surprised if they can still supply or somebody reproduced the part.

Martin

[Dillen]

Some electrical appliance nearby? A refrigerator, perhaps at the opposite site of the wall?

Martin

[Dillen]

Not sure if I read and understand your post correctly, but if the motors in your Beograms are missing altogether, contact me.
I often have original motors in the dungeons, also restored ones from time to time (coming from products that got scrapped decades ago because they were, for other reasons but indeed(!) beyond repair).
Or ask at Beoparts.

The motors used in Beogram 1200 (and motors used in most other Beograms) are perfectly repairable.
Take it apart, clean and lubricate the speed setting mechanism, clean the motor spindle and fit new bearings (Beoparts-shop), and the motor will be back up running as new.
I would prefer that solution to any implant bodge any day. And it will still be perfectly repairable, servicemanual etc. still valid, should the need arise.

Yes, power supplies are basically a matter of voltage(s) and current, but also the amount of emitted noise (electrical, physical and electromagnetical) and something as simple as room for mounting (f.e. Beogram 4000).
In Beograms without RIAA or quad-decoder the power supply has no direct influence on the sound reproduction, since there are no electronics in the signal path.
Only the stabile run of the platter and, for tangential decks, the correct controlling of the carriage movement and the tonearm lowering etc. depends on correct power.

Are you currently facing a transformer problem?

Martin

[Dillen]

Regarding the transformer, it’s simply not possible to make one using an Arduino, a smartphone or a 3D-printer.
Nor is it particularly cheap to have one – or a few – custom produced.
Using a part salvaged from a donor item could be the only feasible way.

The same goes, more or less, for a broken plastic part.
Whereas a plastic part may, or may not, be possible to 3D-print, it may, or most likely may not, end up looking as good as an original part, which could be important in some cases.
In any case it would take time measuring, creating a drawing, doing presumably a couple of test-prints and test fittings, to get the part right.
If it’s a part that breaks fairly often from normal use or wear it will, no doubt, be considered for reproduction by Beoparts-shop (listens and takes notes of all requests and inquiries and never 3D-print anything).
If the part was broken by accident, a used original part may also here be the sensible way as seeing other owners in need of one any time soon would be unlikely.

Complete reproduced circuit boards are rarely needed for the vintage products.
Practically all of the vintage Bang & Olufsen boards can be repaired at component level, and in most cases even the board
itself can be repaired if needed, and again it would be quite costly to develop and produce just a few.
This certainly would be true for boards in almost any modern product, TVs, active speakers and such.

I will not go into discussions about originality, but fitting something “homemade” like f.e. an Arduino in a Beogram would in my
opinion take a lot of the value out of the Beogram.
While the Beogram may end up working for the owner, it may be next to impossible to repair for the next owner or repairshop.
I would hate finding such things inside a Beogram coming in for repairs here, and I would hate having to tell the owner that I cannot help him without fitting back original parts, that would have to come from a scrapped donor.

Martin

[Dillen]

I’m sure it would also be of interest to potential buyers to know where in the world the products are located.

Martin

[Dillen]

In your case:
A leaky diode, perhaps.
A broken copper trace somewhere, perhaps.
A failing SO switch, perhaps.
Any combination – or something completely different.
It’s impossible to diagnose a problem like this from a distance, and the more you
replace, the bigger the risk of introducing new problems, making it even harder to diagnose.
It’s always easier to locate a fault that was caused from “natural” reasons, like aging etc. than one caused by “something been done”.
Blanket replacing components is a typical cause for strange faults.
Anything can happen – wrong components, wrong polarization, bad solder joints, shorts etc. It can give even experienced repairers a good run for their money.
And it wouldn’t fix f.e. a broken copper trace.

You will have to measure around a bit and diagnose the problem properly.
Or take the Beogram to someone who can do it. These decks are worth any repair.

Martin

[Dillen]

1. Possible.
2. Possible.
3. Not possible without the proper instruments for setting the trimmers.
3a. Possible.
3b. One of the worst things you could do.
3c. Worse than 3b.
4. Asking never hurts.

Don’t forget:
5. Get the proper instruments and learn how to do it right yourself.
6. Leave the alignment to someone who can do it.

In your case, respectfully keeping 4 in mind, I’d say 6 would be the cheapest and fastest way, and you will end up with a good result.

Martin

[Dillen]

As already suggested, check the thermal fuse in the transformer as the first thing.
Next, check for cracked solder joints at connectors and at the large capacitors at the back.

Martin

[Dillen]

Plastic lacquer?
I would imagine that could cause static problems.

Martin

[Dillen]

You can’t do ohm readings on a powered circuit.

Martin

[Dillen]

Is it completely dead?

Martin

[Dillen]

My first thought was also, if you had the trimmers mixed up when you fitted them.

Martin

[Dillen]

Very nice finds, indeed.
Here is a Beogram 5000 in palisander (red label), just to give you an idea what it looks like.  🙂

Martin

[Dillen]

So it is.

Martin

[Dillen]

It’s an MPX filter. It grounds remains of the stereo pilot.
You can fit any good similar filter – or ask at Beoparts for a good used original part.

Martin

[Dillen]

I’m still here, but far from as active as previously.
Others have left altogether and found other places.

This thread is perhaps not the best place to discuss it, but I have my reasons for now visiting merely a couple of times weekly rather than a couple of times hourly.
I can only imagine, that other members, be that  “surviving” or previous, have their reasons as well. Perhaps some or all of the reasons are the same.

And I don’t think it has anything to do with the “misunderstandings” mentioned above, really. They merely stirred things up a bit and added energy to the forum life.
But I agree, they seem to have gone as well.

Martin

[Dillen]

So it actually works for a brief moment?

Martin

[Author]

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