I have aquired a Beogram 4002 which, after much work and re furbish,  runs slow, sounds about 10% to my ears. The thumbwheel adjusters speed it up but not to the correct speed. I have an old service doc which shows the on-board trim pots but I am unsure as to where exactly they are physically. The drawing of the board with the trim pots is shown to the left of the switch panel but in reality it doesnt look like the one in the schematic. Could anyone post a picture maybe of the actual board please? 

 

Thanks guys..oh and nice to be back after my long spell of ill health..still enjoying my Beogram 4000..

Hi Stevie, the two pots you want are R15 (33) and R14 (45). Click on this link and look at the image it is the two pots at bottom right corner next to the relay. Of course, the board will be flipped so they will actually be top right corner!

The belts are ok yes? Would like to know your thoughts compared to the 4000 :)

 

Edit - I should have suggested you at least clean or better replace the pots. Also don't forget to centre the fine pots first!

There are several different versions of the Beogram 4002 and the main board
differs in most of them. With that the position of the trimmers.
The Beogram 4002 was produced in AC motor and DC motor versions. The AC motor version
does not have the speed trimmers but instead a phase- (or curve shape) adjustment that in
severe cases can have some influence on the speed.

Some board versions have printing on the solder side of the main board with small markings
of "33" and "45" near the speed trimmers. Some boards have the markings etched into the copper, others
have it screen printed in white or black.
If yours doesn't, the best thing you can do is to check the 4-digit type number found on the serial number label,
there's a label at the back or underneath and a similar one inside on the chassis, near
the mains transformer. The type number is usually in the form of 53xx or 55xx.
Then find a service manual for that particular type.

I can supply new belts if needed.

Martin

Now that's a good point

Thanks to you both so much for the help, I will do some rescearch and get back to you. 

 

Dillen, can you let me know the cost for a full belt set, I will pay how you wish, PayPal, Bank Transfer or whichever you prefer.

 

Thanks Guys..

If you can attach a photo of your board to this thread, we may be able to help you better.
You have a PM regarding belts.

Martin

Howdy. They are immediately to the left of the keypads top left hand corner. They are the only two in that area of the board. You want to turn the one on the bottom counterclockwise to speed it up.  Regards, Jim  Audio-Retro

Hi Olly,

 

Thanks, that is definitley the same as my board with the 3V DC Motor. I stripped and cleaned the motor and re lubed and now is running fine except for an occasional waver and slowing down and recovering again. Maybe the pots are dirty or the relay..

As for comparison between this and the 4000, well not much to report really. I prefer the overall feel of the on/off/speed selectors on the 4002 and it is much quieter mechanically when the arm lowers and raises, but as far as the overall sound is concerned they both sound near identical to me. 

Thanks Jim..

Glad you found the pots ok. Martin is the man to see about belt and capacitor kits for these.

 

Regarding the noise factor I find the 4000 to be far quieter overall (I can bearly hear mine under normal conditions apart from the solenoid and speed change relay) but there is no difference in sound when raising and lowering the arm, and I can't see why one should be noisier than the other???

The motor noise is greater on the 4002 when up close, but from my listening spot it make no difference. The arm lifting/lowering mech is more "clanky" on the 4000 and that is with the dashpot adjusted. The arm lowers nice and slow but the actual mechanism for doing this is much louder. Also even when running correctly I get the feeling that the 4002 is not anywhere near as stable as the 4000, maybe it is because I am waiting for it to wow every so often. As far as the actual sound (music) is concerned, except for the continual feeling of instability they both sound identical of as near as dammit to me. I guess the a/c motor version would sound more stable if my 4000 is anything to go by. I already contacted Dillen re the belts, I maybe will get some when the other problem has been sorted. Is there a cct diagram of the DC version of the 4002 anywhere? I can only get an ac one..

 

Thanks so far.

Is there somthing loose? I wonder if that piece of foam inside the springs is missing - wouldn't have thought it would have made that much difference but maybe so?

Hello,

I guess you meant the 4002 is more clanky!

As far as motor noise is concerned, there is none on my 4002. With my ear stuck on the left side cornet of the plinth I can hear a faint motor noise but it is only just audible!

Have you contemplated a problem with the motor itself? It is of the brushed, Matsushita servo type and they are prone to brush disintegration...

Do you own a scope? You could have a look at the signal to the motor...

I have Beogram 4002, 4004 and two Beogram 6000.

As far as noise goes, I'm not sure what you are talking about!!!

I hear a microswitch avtivate on pressing START and a solenoid click when the needle drops. The reverse happens at the end of the record. That's it!!!

The speed change is silent!

As far as motor noise, there is none. Either AC or DC types. In fact they are so quiet that when running the system without the drive belt, I have to touch the pulley on the motor to check that it is running!

We are not talking about the platter motor? we are talking about the servo, I think! Graham are your servo motors plastic or metal and is there really no sound from plastic versions at all?

I would be very worried if I heard the platter motor at all tbh!

Graham I guess the speed change relay is not as obvious but you can definately hear it - just before the arm is lowered!

 

edit*
Changed because I was a little defensive in my reply when I shouldn't have been... not had me tablets yet :)

I think my servo motors are all plastic. I don't recall any of them making any noise, even when driving the full length of arm travel.

I have replaced all the belts  so there is no slippage on the pulleys.

That is certainly interesting! Maybe the two I currently got have dodgy bearings! Belts are fine. It does sound more like a resonant sound tbh more in line with cheaper motors - I am sure Chartz mentioned his servo being noisy on transitions. He was going to try replacing the foam inside the casing so not sure if that was ever attempted... No doubt he will read this and elaborate :)

joeyboygolf:

I think my servo motors are all plastic. I don't recall any of them making any noise, even when driving the full length of arm travel.

Well my carriage motor has worked flawlessly since the repair, but noise there is most definitely, and it is loud enough!

I have made no attempt at changing the foam inside yet.

I can also hear this motor on my Beogram 8000, even though it is quieter...

The speed change, lower, and on/off relays are quite noisy too!

 

 

chartz:

joeyboygolf:

I think my servo motors are all plastic. I don't recall any of them making any noise, even when driving the full length of arm travel.

Well my carriage motor has worked flawlessly since the repair, but noise there is most definitely, and it is loud enough!

I have made no attempt at changing the foam inside yet.

I can also hear this motor on my Beogram 8000, even though it is quieter...

The speed change, lower, and on/off relays are quite noisy too! 

I've just pressed the START on  the 6000 in my workroom (no record on) and I suppose there is a gentle whine but it doesn't come from the motor. The motor itself is absolutely silent, so much so that without the drive band I cannot tell whether it is running or not.

With the drive band on, the gentle whine comes from the screw drive or the bearings. Whatever, I need to be head under the dust cover to hear it!

No......................The 4000 is more noisy as far as the solenoid operation is concerned. The 4002 is MUCH quieter in actual operation, however the 4002 motor is noisier..

I know what I am talking about!! I own and run them both..I am not and never did talk about speed change. When I press to start the solenoid operation on the 4000 is noisy with a loud Clack..the dash pot is adjusted and the arm lowers nice and slow. The motor on the 4000 is quite quiet after much careful adjustment of the voltage. The 4002 is much quieter mechanically when the arm lower/raise mechanism operates but the Motor is noisy, a very definite "burbled Hum" can be heard quite distinctly from about 12 inches away..

Hi Stevie regards the clanking sound set everything up as per the service manual especially regarding the horizontal position of the solenoid arm - the screws that hold the sol could be loose too. I compared my decks there isn't any obvious difference but they are a floor apart in different environments!

Regarding the motor are you talking about the platter or servo? As mentioned the platter motor should be dead quiet, literately!

Hi Olly,

 

I am talking about the actual tirntable drive motor, with the belt off it is silent, with the belt on it has this "burbling Hum" from all around the motor and the actual platter. I havent done much with it lately as I have been working until late most days but will try to isolate it and also hammer down the occasional speed instability now I have the DC motor cct diagram..Thank you Peter!!!.....

Hi Olly,

 

I am talking about the actual turntable drive motor, with the belt off it is silent, with the belt on it has this "burbling Hum" from all around the motor and the actual platter. I havent done much with it lately as I have been working until late most days but will try to isolate it and also hammer down the occasional speed instability now I have the DC motor cct diagram..Thank you Peter!!!.....

Have you fitted new drive belts??

I use stroboscopic disc and mains lighting at 50Hz. Rotation is very stable.

My turntable drive motors, both AC and DC are absolutely silent!