BeoGram

Re: Beogram 4002 arm lifting too slowly

chartz — Sun, 17 Oct 2010 14:01:54 GMT

Thanks, Menahem. We all keep learning, don't we?

Jacques

Re: Beogram 4002 arm lifting too slowly

yachadm — Sun, 17 Oct 2010 12:25:57 GMT

Well done!

I hate saying I told you so (because I didn't - not this time anyway ;-), but you've just proven to those doubters who think the joints "look clean", that it just ain't so!

Removing the whole assembly and cleaning properly is so essential to achieving flawless operation. It's not even reasonable to assume that any, and I mean any, of these turntables would not require a proper cleaning, once they start exhibiting these symptoms.

Of course, I speak from hard-won experience - I remember the first BG4002 I did - I tried to get by with a few drops of Singer oil - it worked - I returned it to the customer, and back it came after 2 weeks. Then I did a proper teardown, with no cutting corners.

Menahem

Re: Beogram 4002 arm lifting too slowly

joeyboygolf — Sat, 16 Oct 2010 14:04:14 GMT

joeyboygolf:

Good Luck putting the clip back on!!!!!

...........even with circlip pliers I've managed to loose two.......ping

Re: Beogram 4002 arm lifting too slowly

Step1 — Sat, 16 Oct 2010 13:47:45 GMT

Yes I guess circlip pliars would be useful here!

Re: Beogram 4002 arm lifting too slowly

chartz — Sat, 16 Oct 2010 09:16:21 GMT

joeyboygolf:

Good Luck putting the clip back on!!!!!

I sense some bad experience here... let's see...

Re: Beogram 4002 arm lifting too slowly

joeyboygolf — Sat, 16 Oct 2010 09:09:05 GMT

Good Luck putting the clip back on!!!!!

Re: Beogram 4002 arm lifting too slowly

chartz — Sat, 16 Oct 2010 07:40:14 GMT

Problem solved.

When I dismantled the bottom lever (the one with the circlip) I had a very hard time to take it up... Once cleaned and oiled, off we go!

Oiling it superficially won't do. You really have to remove the thing completely. Be careful because it will come off all of a sudden, after lots of efforts, and the arm is not very far... Also, it may be wise to unsolder the coil... Note that I haven't inserted the clip back into place yet.

Something I don't like the stud-bending affair to place the alu plates correctly!

Anyway, another classic Beogram saved from the tip!

Jacques

A small video here

Re: Beogram 4002 arm lifting too slowly

Step1 — Sat, 16 Oct 2010 03:18:54 GMT

One more thing make sure the restong position of the lower arm is parallel to the adjacent PCB when the solenoid is at full deflection this is also important!

Re: Beogram 4002 arm lifting too slowly

Step1 — Sat, 16 Oct 2010 03:16:26 GMT

chartz:

Step1:

Have you cleaned and lubed the angled arm that transfers the solonoid motion to the picup arm?

Well it didn't need to be lubed.

The deck is in good condition and lubrication was no disaster, except for the main bearing (dry sintered bronze).

Anyway it plays records now, no rumble or hum, just music!

I just think there must be some problem with the damper cylinder, the stylus lifting veeery slowly but the descent being just within tolerance (1 sec.). Insufficient solenoid power an option?

Any further advice appreciated of course!

ok you might as well remove the arms, springs and damper and clean and lube with some good quality mineral oil (singer oil is great stuff). Especially the pivot points - these can offer enough resistance to completly sieze any part of the mechanism!! Watch those spring clips though!

The damper can be removed and cleaned with a clean lint-free cloth ( I also use isopropyl ) and again use a good quality mineral oil to return normal operation.

chartz:

Is there a valve that could be obstructed?

Also, I am not afraid putting everything into bits and pieces!

Ah now I am not too sure but try to do as above and all should be ok.

Re: Beogram 4002 arm lifting too slowly

Søren Mexico — Fri, 15 Oct 2010 21:29:25 GMT

Jacgues

Please keep us posted about this, you did again an amazing job and we are waiting for the last little perfection.

Beogram 4002 arm lifting too slowly [solved]

chartz — Fri, 15 Oct 2010 15:44:39 GMT

Dear all,

This is a re-post of my conversation with Step1. So far:

Success!

Thanks to all who helped me, from the bottom of my heart.

The only thing which is a bit scary really is that I'll never know what happened the first time around... will it happen again?

The arm, after shutter alignment (I had some experience with my 6006 and 8000!), tracks perfectly. Automatic speed change works too.

My remaining problems are:

- the arm which doesn't go up quickly enough (even after lubrication),

- the manual movements which are too slow (this shouldn't be too difficult, there are trimmers).

Let's have a look at the other posts now: homework time!

Step1:

Have you cleaned and lubed the angled arm that transfers the solonoid motion to the picup arm?

Well it didn't need to be lubed.

The deck is in good condition and lubrication was no disaster, except for the main bearing (dry sintered bronze).

Anyway it plays records now, no rumble or hum, just music!

I just think there must be some problem with the damper cylinder, the stylus lifting veeery slowly but the descent being just within tolerance (1 sec.). Insufficient solenoid power an option?

Any further advice appreciated of course!

Step1:
[...]you should see that the damper retracts very quickly with the vertical lever I mentioned above following it!

That's my point, the damper retracts very slowly when it is free!

Everything is intact, and I do manipulate, and love it!

The mechanism is lubricated and everything moves freely, except for the damper. Is there a valve that could be obstructed?

Also, I am not afraid putting everything into bits and pieces!

Step1:

Ah ok have you ever had the piston out of the damper? I would do that and clean up then relube..

No, no. The thing is, you just can't relube with ordinary grease, can you?

I have arm damper fluid (polydimethylsiloxane, 600,000 cst) in stock which could be used.

Have you done it yourself?

If so, could you tell me how you (or anybody else here!) did it please?

Many thanks,

Jacques