Hi All,

My Beogram 4000 has been making a nasty noise while the arm travels to the record and back.

I have attached a video for anyone that might have a clue what i can do.

Remember to have your sound turned on.

I tried to imbed it but it doesnt seem to be working so just copy the link.

http://s1042.photobucket.com/albums/b424/ifoldaway/?action=view&current=Beogram4000noise.mp4

Thanks in advance

Tom

Format: mp4
Duration: 20 seconds

I am afraid that sounds like a very poorly servo motor. This should be whisper quiet. You can try stripping it down and re-oiling (with very light machine oil such as singer for sewing machines NOTHING else!) but from what I have seen in the past once it gets to this stage there is very little that can be done, as the sintered bearings are probably ruined. If you do pull apart check the brushes as these are sometimes near the end of life and if so can cause a short which has other (not too serious) consquences.

I can give tips on how to put the back back on the motor without knackering the brushes should you require!

I would also check the main bearing and main motor at the same time make sure they won't get (if not headed that way already) in a similar state. With the main bearing on a 4000 I take the belt off run the platter up to 33 1/3 using a strobe disk then time how long it takes to stop. Typically you should see > 2 minutes. Again clean old oil away as it could be anything in there and re-oil with singer the main bearings and check the thrust plate is ok at the bottom and not pierced or badly indented.

Regarding the servo the man to contact is Martin (member Dillen) who may be able to supply you with a suitable replacement or give you further advice. I am currently talking to a rep at the original manufacturer and meant to talk to Martin about this (it only started out as a small enquiry after coming across a few examples like yours!) as I have a feeling more and more of these motors will be failing either due to knackered brushes or failed bearings or both! It seems there is a very similar unit but I suspect it will be very expensive, in the order of about £80!

Cheers for the swift advice.

The sound doesn come andd go a bit , so i would hope i can try and fix it before looking for a replacement.

I have the service manual but having never taken the turntable to pieces before, would you say its an easy job?

How difficult is it to remove the motor and place back in?

If its something that should in no way be touche then any ideas who i could take it to?

Thanks

Tom

Tom the motor is actually easy to access. The whole wooden trim moves forward, thus releasing the upper panels. The correct way of acheiving this is as follows...

Firstly sometimes it is easier to slightly move or remove the dustcover as I have known it to press hard against the panels making them harder to remove. his is easily ahieved by allowing the rear of the turntable to overhang a table edge revealing the two large flat blade bolt heads (recessed under the deck either side near back edge). I then open the lid, slightly loosen the bolts then slide the entire assembly off the back fo the deck.

WIth this being your first time I would also move the tonearm in toward the centre using the controls then unplug the deck - as it is the right rear panel you are interested in at the moment this will give you some more space to work with and allow easy removal of panel and motor. It should be mentioned however it will make it harder for you to remove the main panel and platter. But why not take one step at a time hey? This will reduce any likelyhood of mistakes and the temptation to touch other parts will be removed :)

At the very least put protection over the stylus better still very carefully remove from the arm. Make sure you pull in the angled direction in a downward manner dead straight - I prefer to wiggle in small movements side to side - this will minimise the chance of snapping the delicate cartridge mount.

Now, the proper way of pulling the plinth forward is by using a flat blade object to release some tiny clips that are located between the wooden plinth rear and the chassis on either side at the rear of the machine, the whole wooden plinth (all three sides together) can then be pulled forward. Often you don't have to bother with the tiny clips as people just tend to perform the usual of pulling the wooden trim forwared without thought to the clips and this weakens them sufficiently for them not to work anymore. Once the wooden plinth is fully forward you might notice the panels jump a little.

You can then remove the right rear panel by lifting its right edge up slightly (about 1cm) and sliding to the right. You will then be able to see the servo motor in a black(or less commonly white) casing. You will need to unsolder two wires (noting which way round they are - if you have moved the whole assembly enough to the left these should be easy to access) and then remove the servo belt. Now you can remove the motor with the four screws, the casing splits in two halves and the motor drops out. Dead easy for the experienced it is literately five minutes but please don't rush and take your time.

Lest us know when you get to this stage.

BTW talk to Martin Olsen (Dillen) if you haven't done so already he cannot uforntunately access these forums atm which in my opinion is not good enough for such an important contributor - but I guess that is for another thread!

Let us know how you get on.!

Sounds like an ideal christmas project!

I will give this a go, any advice once i have removed the motor? 

Should i completely strip the motor or just apply oil in key places.

Is wd40 any good or should it be specialist fine oil? Just saying as i have some here with me.

If its a strip down, is there any detailed instructions or a video anywhere to act as a guide?

Thanks for all your advice so far Oli, you really are a star an i cant wait to have my BG4000 working smoothly again.

Tom

WD40? Absolutely forbidden!

This is just good for unlocking rusted bolts!

You may use sewing machine oil or even Mobil One!

Olly has an early Beogram 4000 and on later models the bearing is not as good, so I'd say one minute tops.

About the carriage motor, the one on the final 4000s is the same as on the 4002 and it is much noisier. Yours is exageratly so though, and inspection is required. On my 4002 it kept frying transistors because it was dirty. It is however à quality Swiss, long life motor so à good cleanup might be enough... Its bearings had no play on mine.

There is a small access cap on the red side for such maintenance, but you MUST be extremely handy!

The word WD40 should be treated as a swear word round here! Best leave that for loosening nuts I wouldn't even use on hinges or my bicycle lol! it is not a lubricating oil it is a Water Dispersent hence the letters WD!

Anyway, the stuff you want is Singer oil, either at a local sewing shop or on ebay? If not singer make sure it is a light machine oil. Any thicker will risk cloggin the pores of the bearing. You should really extract the old stuff by heating and then soak the new stuff in using a similar method but this is a little impracticle, if not impossible unless the bearing itself can be isolated.

regarding the stripping of the motor IMO yes it is nescesary I usually pull it apart clean the shaft and soak the bearings for some time. The back end comes off easily if you carefully pry off with a razor and there is a small circlip at the pulley end of the motor this holds the rotor in place. Remove carefully without distorting (you will have to replace if you bend it) and watch for the washers and the order in which they are removed. The lot should slide out the back end now.

Great deal of care must be taken as these are ironless core motors and can be damaged if you handle roughly.

Getting back together is fidely with the brushes but you can roll a piece of paper in such a manner as to assist in returning things to normal. I could provide a picture if required.

All the above is often enough to quieten a motor down but I suspect your example might be beyond this stage now. Worth trying though!

Hi Jacques have you seen plastic motors on the 4000? I ask because I know the metal motors appeared in early(?) 400x decks usually with an ac motor... Nothing surprises me with these decks though lol!

Regarding the access cap at the rear I think that was originally designed for assembly purposes - There is no access to the rear bearing here and putting oil in this end only risks flooding the small gaps between stator and rotor windings - this ironically might help with a noisey motor but I think a recent example I had with peeling tape on the rotor windings might have just been such an example of oil getting where it shoudn't!

Yes I have a 4002 motor on my 4000. The hole was useful to me, it was possible to see the problem and take/maintain the brushes away!

Ok, i will leave the WD40 where it is and get some sewing machine oil.

Thanks for all your advice. I will give it a go as i am fairly handy.

Any pics showing the internals or a video would be very handy though

Thanks

Tom

Tools required:

thin blade / knife

fine tweezers

contact cleaner (e.g. servisol 10)

helping hands

fine nose pliers to replace circlip

Singer oil.

A trip to Maplin or other electronics store will be beneficial.

Firstly remove the back end carefully with a sharp knife. You are not cutting but levering here - I normally move to the back of the blade...

The brushes

Remove the circlip and washers...

Front bearing to be relubed...

Rear Bearing to be relubed... Just visible but recessed.

The shaft - I normally give a clean and remove the washer at the bottom and clean this too. Then a dab of oil.

The fidly bit - Reinsert the rotor into the motor body, making sure any washers are present. Add the one or two washers to the end and then line the circlip up with its groove in the motor shaft. Very carefully squeeze back on with pliars. Do this in such a manner that should the thing ping off it can't go far because finding one of them in the carpet is not fun!

The brushes will have likely crossed over. At this point use some fine tweasers to reverse them and open them up. Then I have a rolled peice of paper ready and insert from the rear through the access hole. Release brushes and allow them to sit against the paper - whilst the paper is allowed to open up in the hole. This is a good opertunity to spray contact cleaner onto the paper and clean the brushes by rolling a few times not against but with the direction of the brushes.

Place rear plate back on the motor making sure to line the raised buts it should now click in place slowly revolving paper whilst you withdraw..

.

Simple job just a little fiddly - Take your time!

At this point I normally run for a while on my bench supply to establish everything is ok...

Edit to add a couple of bits of info...

Superb step-by-step(1) instructions Olly!

My motor doesn't look like this at all! Oh well...

By the way, I used a hollow plastic Q-tip rod which I cut off to do the brush job (the axle just fits in), but paper seems much safer... Good idea Olly!

Is yours a Maxon Jacques? Maybe ask Martin but I wonder if yours was swapped at some point in the past? I am sure they would have been quieter when new but IMO the plastic definately adds resonance to any noise!

I have sent the details about replacement motors to Martin so will be interesting to see what he has to say on the matter.

Here you go, sorry about the quality!

Beogram 4000 noise

Setting the wormscrew parallelism (a pig of a job, this) and lubricating it (Martin recommands teflon charged oil) is also paramount (I like this word!) for the motor to run smoothly.

In later Beogram 8000s the wormscrew was guided at both ends and I think it's more elegant. More so than the thread used in my 5005!

Hi Jacques yes you make a very good point there. A very good way of ensuring the screw thread is ok is to measure the motor current as it traverses. Seeing a nice low current and more importantly an even current drawn across the range is a good way also make sure that the angle bracket holding the bearings is square. Teflon oil is good on the plastic bearing.

I think anyone can get these decks running in about an hour but it takes a heck of a lot longer to set them up for optimum performance! Another thing I have recently noted is that it can be beneficial to strip the main horizontal ball race bearing... I know it is a big job & rewire (you could use the old enamled wire but I prefer to replace I know less likely to snap and easier to re-guide long strands) but there is no way of knowing how free the ball race's are until you pull it apart - one I recently did was clearly not performing as freely as it did after I had stripped and relubed - but it is not really possible to tell looking at or manipulating the arm! Seriously the more I work on these decks the more I see needs doing to them!

Superb instructions!

I will go for a trip to Maplin for suppies then give this a try over the holidays.

Ill report back with pics.

Thanks again all

Tom

Step1:

 

Firstly remove the back end carefully with a sharp knife. You are not cutting but levering here - I normally move to the back of the blade...

So that's how it's done!  Outstanding procedure - I'm not sure I would have the guts to try.

Done it twice, don't be put off. You just need à steady hand!

I've just finished replacing the complete switch assembly on my Beocord 2200 and this was difficult!

chartz:

Done it twice, don't be put off. You just need à steady hand!

I've just finished replacing the complete switch assembly on my Beocord 2200 and this was difficult!

Too late now, Benny Amina replaced my BG4002 motor last summer.  Hopefully it will be many years before I have to do that!

On the other hand, I should have my BC5000 Type 4716 tomorrow....

Hey hey hey, 4716, same as mine!!

4715 for me, what does that mean I wonder? Just checked it is dual capston...

@Rich do you know if he replaced your motor with a s/h unit, new old stock or something from a different source all together?

I think 4716 was the US version 120V/60Hz, but I'm not 100% sure.

I do not know what Benny put in my BG4002 for a "new" motor off the top of my head.  I will check his service receipt this long holiday weekend and report back here.  I may be completely wrong here, but I get the sense Benny may use rebuilt parts he has on hand in sort of a rolling fashion.  For my BM4000, maybe he simply took out the amplifier board and replaced it with one he already had rebuilt.  He will then use my former board for the next BM4000 repair.

Like I said, though, I may be completely wrong.

My receipt from Benny doesn't have any details regarding the motor. I'll take a look inside sometime this weekend and take a picture.

By the way, I'm still looking for an original servo pulley (the big one with à half-moon centre hole)... 

Anyone please?

Hi Jacques the thing is many of these are much the same, so no guarrentee your replacement will be any different! I think this is one part that could do with a retooling - I thought about a brass collar like you find with Mecanno stuck to original nylon pulley, if you could get it to stick!