The little black plastic tab is circled in red.

It is called an "eccentric", because when you insert a small flat screwdriver and rotate it, it causes the mechanism underneath to displaced in an elliptical motion.

The objective is to find the sweet spot, where no buzzing occurs when you push the LIFT button, and the Tonearm moves correctly towards the LP.

Click on the picture to display it fully.

BTW, I drilled an exact position hole in the underplatter, to provide easy access for adjusting the tab, without having to remove the belt and underplatter each time I needed to adjust the tab, in 10-degree rotation increments.

Also, because you do NOT install the main platter during these adjustments, and because the platter mechanism needs to be weighted down, so I put a roll of solder in the center of the underplatter.

If not weighted down, the belt unravels during rotation!

This is the underside of the LIFT button

This is a really dirty switch,  sick with oxidization.

Repeated wipings with a Brasso-impregnated strip of thin cloth solves the contact problem.

Again there is a sweet spot for a correct contact, by releasing 1/4 turn the bolt which secures the black-plastic housing to the aluminum chassis, then rotating the black housing until the switch works just right - no buzzing. Resecure the bolt.

The machine has to be upright on blocks to provide correct access and view from underneath.

I don't have any pictures of the voltage switch.

However, this is the procedure.

Lay down a white sheet on the floor on which you and the BeoGram will sit, and that is where you are going to do this procedure, because the little spring and ball bearing are sure to jump away from you, because at this stage, you are not accustomed to the correct way to do it, without losing these tiny parts.

The black voltage switch must be lifted away from its holders, so that you can turn it over, and expose the underside clearly.

Do NOT disconnect any wiring.

In the square centre of this switch bottom, are 2 flat (but triangular) plastic tabs, which are part of the upper cover, which push down through the switch's centre, and grip the bottom half of the switch.

With a pair of flat-nosed pliers you will grip these 2 tabs and squeeze them GENTLY towards each other, while encouraging the upper cover away from the bottom part.

It will help if you have a friend to do this with you.

The spring and ball bearing will jump away from you during this time, and you will find them on the white sheet.

You have now opened up the selector switch.

There are many little bits of metal which all need to be Brasso'd until absolutely shiny, wiped off, and then wetted with contact cleaner.

Do NOT wipe off the contact cleaner.

Don't worry about reassembly - it can be assembled ONLY in the correct alignment.

Play with it before final reassembly, to ensure that you understand the alignment.

I hope that's all clear!

Ah, you're awesome.  Thank you!  I'm on a train home and will get on this as soon as I have dinner. 

But, it occurs to me that you have the 1203 whereas I have the 1200.  I'll send pictures of the insides of mine, but I can see there are differences--your lift button has entirely different mechanics from mine. 

ill upload pics when I get home--the project for tonight will be the voltage selector (thanks for the detailed info).  

The buzzing sound aside--the motor should run even if the buzzing occurs, right?  

I don't have the 1203, or the 1200. All photos were taken many years ago, when I had a particular model in for service.

However, the entire 120x, 2000, 3000 series ALL operate the same, and use 99% identical parts.

Take a close look again at your 3000, and you will see that everything to which I referred, is there, just as I described it.

Thinking of correct operation, the motor starts after the buzzing stops - of course, the buzzing shouldn't be there anyway.

The buzzing is the "bad" start of the rotation, so buzzing means that rotation was not able to start.

Menahem Yachad wrote:

However, the entire 120x, 2000, 3000 series ALL operate the same, and use 99% identical parts.

😕

I continue to be amazed at how different we see things, Menahem.
- And how different our experiences are.
I have repaired hundreds and yet hundreds of Beograms of these types and yet, you often
suggest repairs to areas that I never ever saw a problem with and would never dream of focus'ing on.
I have seen very few bad power selector switches in my life and they were either broken by misuse or
damaged by water, lightning strike or something else uncommon.
If oxidated, just rotate back and forth a couple of times and they'll be fine.
And they were all in Beomasters - never saw a bad one in a Beogram.
I'm not saying that it cannot happen - of course it can, lots of things can happen and things
could easily be different in other territories due to temperatures, weather, airs moisture etc..
It's just not something I have seen here - even on decks from the middle-east or Asia.

Your experience is that practically all of the AC-motors are still running fine - mine is
exactly the opposite in that almost all decks of these types that I have on the bench is in need
of a thorough motor/bearing service.
Some have seized to an extent where, if you rotate the motor spindle by hand, the spindle is not
rotating in the bearings, - it's the bearings that are rotating in their holders.

But let's stay with facts. We cannot disagree on facts - can we?
Well, perhaps, unless we disregard your saying that Beogram 1200, 1203 uses
99% identical parts - because that's simply not true.

Despite some of the operation principles and design similarities Beogram 1200 and 1203 share only very few
components - apart from a few screws and other minor parts they are almost entirely different.
The operation is different, buttons are different, suspension different, tonearm, electrics, adjustments etc.
(And that goes for both versions of Beogram 1203, which again are far from identical inside).
Beogram 1203 is full-automatic, Beogram 1200 only semiautomatic.

And Beogram 1200 doesn't have any of the contacts and adjustments you refer to.


And then my attempt to help Honza;

If very faint, the buzzing will most likely come from the motor. If very audible it could be an oxidated switch, but that's rare.
The vast majority of these AC motors will have seized up in old and dried lubricants to some
extent by now and will be in need of a thorough service. That's quite normal.

When you tell, that the deck is buzzing and the motor warms up, it could confirm that
the motor has seized.

Is the belt on correctly?
Does the motor rotate easily by hand?

Martin

Martin

Because I may have been amiss in not being absolutely clear, allow me to clarify the above statement - "However, the motors of the entire 120x, 2000, 3000 series ALL operate the same, and use 99% identical parts". And that's what we're focused on here - the motor function.

Anyway, sorry for the unintended misunderstanding.

Regarding the rest, however, I can speak here based only on experience.

I have had to rebuild the motor only ONCE, in about 25 years, over tens of these machines. And that was so unusual, for ME, that I made a thread about it here on Beoworld.

Any time that I have a slow-running motor, which would by all symptoms appear to be seized, I always overhaul the AC selector. And that's always solved the problem (of the slow motor, that is). So, for me, that's my "goto".

Every tech has his automatic list of "goto" fixes in priority order, when he is familiar with a particular series of machine. That "goto" priority is based on that tech's personal experience.

So, I'm sharing my "goto" list, which may or may not be similar to yours, and that's just fine.

The important thing is that the owner covers all possible bases, and ends up with a fully-functioning machine, and a smile on his face.

All done in good spirit, and no offense taken when we differ 🤒

As far as overhauling the motor, go for it. You've done many more than I (exactly one), and Honza deserves the best advice possible.

Menahem

Hi everybody,

thanks for the variety of responses.  

Menahem--I looked at the voltage selector, but it didn't match up your description; there was no way for me to dismantle it other than cutting it in half, so I didn't.  See pictures below.  However, I did use some contact cleaner on it AND AFTER I DID THE MOTOR STARTED MOVING!  Only about 15 degrees in the 10 seconds that I plugged it in, but better than nothing.  

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I think applying electrical contact cleaner is about as far as I can get with this voltage selector.  Do you think otherwise now that I supplied pics?

I got a voltage checker so that I can double-check voltage around the circuit--does anybody know how much it should be?

I can now also confirm--thanks Martin--that the buzzing comes from the motor.  I turned the voltage selector to 110V briefly and it started moving a bit more and buzzing a lot more.  So I think a clean and oil is in order.  I have brasso and the contact cleaner.  I also bought a thing of sewing machine oil.  Are those all the tools that I need?  Is there a guide on how to properly clean and lubricate these motors somewhere?  At the beginning of this thread the guy showed some pics of the disassembled motor but I wonder if there's is a bit more in terms of know-how.

Also--here are just general pictures of the deck in case any of you see something out of the ordinary.

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Thank you again for all the help!

Wow! You refreshed my memory of those Voltage Selectors which I haven't seen, for I don't know how long. Those are riveted, and not able to disassemble.

The best is to spray contact cleaner in through the wiring holes from underneath, in the hope that some fluid will penetrate to the contact.

I would also check the ohms between adjacent wires. The reading should be either less than 1 Ohm (closed, with the contacts in good condition) or some KOhms (open, but in the circuit).

If you see that some reading is higher than 1 ohm, then the associated contacts are oxidized, and further work is necessary.

Understand that the higher the ohm resistance on those contacts, the LOWER is the voltage reaching the motor, which reduces the motor's ability to rotate correctly, if at all. 

When those contacts are shiny clean (which in your case you cannot see) and provide ZERO resistance to the required voltage, that well-engineered motor rotates perfectly, assuming no detritus in the motor bearings - as Martin described.

Martin asked previously how does the motor feel to your fingers, if you rotate the brass pulley cone by hand, with the platter and belt off. 

Thanks!

And sorry about not answering Martin's questions--the brass pulley is VERY hard to rotate by hand, so I think it's a case of a stuck motor.

I know this is probably the dumbest question, but how exactly should I measure the resistance?  I'll set my voltage meter to ohm, of course, and then just make my way between the cables, doing, e.g., red & brown, then brown & blue, etc., as I complete the circle?

Honza