BeoGram

Re: Beogram 4002 no arm movement

chartz — Tue, 09 Nov 2010 07:57:03 GMT

Same here! Our wives could be friends and tell each other nasty things about us!

Re: Beogram 4002 no arm movement

Step1 — Tue, 09 Nov 2010 07:51:02 GMT

In all honesty I have a wonderful understanding wife. You would know that if you saw the state of my 'computer workstation' behind the setee - my excuse is that if I took it all upstairs I would rarely see her!

Re: Beogram 4002 no arm movement

chartz — Tue, 09 Nov 2010 07:12:10 GMT

Step1:

the misses has said one has to go now - Looks like my B&O is going to have to earn it's keep in my house :(

Oh well don't we love them Ollie? I mean the good ladies!

As for me, I have plenty of room in my house!

Re: Beogram 4002 no arm movement

Step1 — Tue, 09 Nov 2010 06:17:36 GMT

Glad to hear things are doing well Jaques :) I just bought another 4002 for restoration and the misses has said one has to go now - Looks like my B&O is going to have to earn it's keep in my house :(

Re: Beogram 4002 no arm movement

chartz — Tue, 09 Nov 2010 03:54:11 GMT

Hello,

For those who used to follow this thread (thank you again) the 4002 is still working fine!

Re: Beogram 4002 no arm movement

Step1 — Fri, 29 Oct 2010 17:40:29 GMT

Yes the solenoid probably draws about 3 amps for 20ms or so - There will be quite a strain on the supply!

Regards the bulb, you mean the detector bulb? If so yes R36 and TR5 is effectivly a potenial divider delivering 9v to 15v ZD17. Bulb fails voltage raises and ZD17 breaks down forward biasing TR6. If you mean the 33 bulb then there is no effect as far as I can see.

Re: Beogram 4002 no arm movement

chartz — Thu, 28 Oct 2010 03:41:19 GMT

Hi,

Is it normal that the 33rpm bulb blinks as the relay clicks when the arm detects the start of the record?

After the diagram, it seems that the bulb is an important part of the circuit. I guess that if the lamp is shot, detection won't work, or will it?

Re: Beogram 4002 no arm movement

chartz — Wed, 27 Oct 2010 07:59:08 GMT

Yes I also expected carbon brushes!

I've seen too many disintegrated metal brushes in cassette decks!

The problem is they can't be repaired easily.

On my motor they do show wear. I'm pretty sure the metal dust that had gathered between the brushes and the rotor made the motor more silent, but the bad contacts caused the problem because of arcing.

Re: Beogram 4002 no arm movement

Step1 — Wed, 27 Oct 2010 06:37:52 GMT

Nice shot Mika! Thinking back maybe my motor did have a red back end...

Looked at my spare metal motor last night (with grey back end) and this has a similar hole revealing leaf brushes. No cap though. Obviously very nice motors but I would have thought they would have used carbon brushes...?

Regarding the compressed foam I suspect it will make little difference to replace it but it could be worth a try I suppose!

Re: Beogram 4002 no arm movement

chartz — Wed, 27 Oct 2010 01:58:00 GMT

Thanks for the picture Mika! This is the one indeed!

Re: Beogram 4002 no arm movement

Søren Mexico — Tue, 26 Oct 2010 14:30:25 GMT

Jaques

You did so many fine repairs on it, dont stop now, change that foam, if the motor has kontakt to a hard surface you vil have noice and the foam has the same age as the TT, think about driver foam, same sh***

Re: Beogram 4002 no arm movement

tournedos — Tue, 26 Oct 2010 13:57:56 GMT

Let me cover for you

Never would've noticed that red cap! And the brushes are tiny...

The foam is perhaps 3 times thicker at the places where the shell hasn't compressed it. It might allow a bit too hard contact with the shell when the belt is pulling the motor to one side as well.

Re: Beogram 4002 no arm movement

chartz — Tue, 26 Oct 2010 13:28:44 GMT

Pleased to meet you Olly!

No, silly me I forgot to take a photo while working on it. The motor is a Maxon Swiss made motor. Interestingly, there is no bearing on the brush side, which makes it easy to maintain.

Re: Beogram 4002 no arm movement

Step1 — Tue, 26 Oct 2010 12:38:42 GMT

Have you got a piccy of your motor. I don't remember a red cap but I will check. My 4000 has a clear end cap which allows you to see the brushes but sure they aren't accesable. my other spare has a grey plastic end. There are obviously a few varieties!

My name is Olly BTW. I must do a 'Mika' and put my name down in my sig!

Re: Beogram 4002 no arm movement

chartz — Tue, 26 Oct 2010 12:20:30 GMT

Hi,

I didn't use any spray, I just rubbed everything with impregnated paper, a bit of brasso too. I re-lubricated the ball bearings though. By the way I ended up opening the thing. You can actually take the red cap quite easily. The hardest is to take the pulley out!

As for the foam, I put the original back on, but changing it is an interesting thought, because then motor didn't seem so noisy on the kitchen table!

Olly, keep us informed!