BeoGram

Re: Beogram 4002 running slightly slow

Step1 — Sat, 12 Feb 2011 11:27:13 GMT

Very glad to hear it :) Did you place the cork between plastic casing for the motor and chassis or between motor and casing? Might try that myself!

Re: Beogram 4002 running slightly slow

Stevielux — Sat, 12 Feb 2011 03:42:43 GMT

Hi all, at last a quiet 4002 and now completely stable all the time. Thanks everyone for their help and advice. I replaced the on board resistors which were a bit flaky and removed the old isolation gunge from the Motor and replaced it with a piece of thin cork. Originally the motor was getting mechanically coupled to the main chassis with the drive belt on and not so with it off, also as there was damage to one of the motor screw threads the motor was slightly loose in its mount. With the thread repaired and the piece of cork stuck to the motor base it is just lovely....'Took me a while as I work long days here and get back quite late in the evening. Playing J.Cash as I type. These really are quite nice pieces of engineering and sound better than the "Hi-Fi" pundits would have you believe.

Re: Beogram 4002 running slightly slow

Stevielux — Fri, 03 Dec 2010 10:38:23 GMT

chartz:

Tell us, did you replace or clean the two speed adjustable resistors? A bad contact at the cursor could generate that sort of thing.

Replace or clean those R1 and R2 adjustable resistors. Do you have any skills (like building kits) in electronics?

Also a noisy motor usually is more obvious when turning without its belt... So my guess is an electronic fault but then the deck is at your place!

Hi Chartz,

I haven't replaced anything as yet, no time for now, but thanks for the advice..always accepted, never rejacted..

Yes I cleaned and checked all the adjustable resistors some time ago, the problem still persists.

And yes I have Electronic skils, 22 Years in the Royal Air Force as an Electronics Engineer on Radar, Boimedical Electronics and the like, so have plenty of experience, Just at the time didn't have recourse to a CCT Diagram (which I now have thanks to this very site), so was just looking for a "short cut" if you get my drift. I also always go for mechanical issues with any electronics as most of the time the issues are usually the mechanical parts thereof. Also from my experience with the 4000 and other such B&O equipment I am aware of the overall good design and general reliebality of their kit.

Now I have the CCT diagram I will 'scope the Motor supply over the weekend to see if all is ok, as an aside I have quite heavy DC on the mains here and had to trim the Motor supply for my 4000 (ac motor) to get it to run quietly.

Will update with scope shots, and general piccies as I progress.

Steve F

Re: Beogram 4002 running slightly slow

chartz — Fri, 03 Dec 2010 08:36:07 GMT

Tell us, did you replace or clean the two speed adjustable resistors? A bad contact at the cursor could generate that sort of thing.

Replace or clean those R1 and R2 adjustable resistors. Do you have any skills (like building kits) in electronics?

Also a noisy motor usually is more obvious when turning without its belt... So my guess is an electronic fault but then the deck is at your place!

Re: Beogram 4002 running slightly slow

Stevielux — Fri, 03 Dec 2010 04:50:37 GMT

No new drive belt as yet, the old one is a very good (ie not loose) fit and when playing is very stable for most of the time, just the occasional wow and then back to speed again. 'Happens roughly every 10 or 15 minutes or so, sometime goes for a whole side without doing it..Motor has nice torque, belt is good and clean. My guess is maybe the relay contacts maybe..The motor noise is only with the belt on, with the belt off it is as silent as a silent thing in silent land, on a silent day..

joeyboygolf:

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!

Re: Beogram 4002 running slightly slow

joeyboygolf — Thu, 02 Dec 2010 15:01:38 GMT

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!

Re: Beogram 4002 running slightly slow

Stevielux — Thu, 02 Dec 2010 14:33:02 GMT

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!!!.....

Re: Beogram 4002 running slightly slow

Stevielux — Thu, 02 Dec 2010 14:32:35 GMT

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!!!.....

Re: Beogram 4002 running slightly slow

Step1 — Tue, 30 Nov 2010 17:51:46 GMT

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!

Re: Beogram 4002 running slightly slow

Stevielux — Tue, 30 Nov 2010 14:42:32 GMT

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..

Re: Beogram 4002 running slightly slow

Stevielux — Tue, 30 Nov 2010 14:35:37 GMT

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..

Re: Beogram 4002 running slightly slow

joeyboygolf — Tue, 30 Nov 2010 06:03:31 GMT

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!

Re: Beogram 4002 running slightly slow

chartz — Tue, 30 Nov 2010 02:21:19 GMT

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!

Re: Beogram 4002 running slightly slow

Step1 — Mon, 29 Nov 2010 16:12:24 GMT

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 :)

Re: Beogram 4002 running slightly slow

joeyboygolf — Mon, 29 Nov 2010 16:01:00 GMT

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.