BeoGram

Re: 4002 tonearm not lowering

joeyboygolf — Sun, 16 May 2010 23:35:26 GMT

I had a Beogram 4000 with complely seized pivot bearings. I had to completely dismantle them as no amount of solvent would penetrate. Just a thought.

Re: 4002 tonearm not lowering

4decksam — Sun, 16 May 2010 22:43:09 GMT

Hello,

Pretty sure the damper/coil are moving/lubed. first thing I did when I opened it. It must be an electrical fault.

Wish it was easy to find.

Sam

Re: 4002 tonearm not lowering

robz — Sat, 15 May 2010 07:53:48 GMT

Here's another thread to look at if the above does not resolve your problem...

http://forum.beoworld.org/forums/t/4595.aspx

Re: 4002 tonearm not lowering

yachadm — Thu, 29 Apr 2010 23:22:28 GMT

Sam,

re 1 - I'm sure that your slide circuit works - the pic shows the LED which is part of the signal circuit (for lowering) - remove the slide-ruler and check that exact LED for function (voltage drop). If that LED does not check OK, the arm will not drop.

re 2 - You will not see a Yellow LED, you will see an incandescent lamp, which should illuminate. If it doesn't, it needs to be replaced. I replace it with an LED, see the pdf for exact instructions.

Re: 4002 tonearm not lowering

4decksam — Thu, 29 Apr 2010 21:15:54 GMT

Menahem,

thanks for the advise, I was about to give up! I'm glad someone with great knowledge is willing to help.

1) I believe the slide circut works. When I soldered the collector/transistor back into the board I had a cold joint and the tone arm just moved across the LP. Resoldered the transistor and whola! back to what I started with originally.(just the tone arm not dropping)

2) I'll have to check out the pivot control however, I don't see the yellow LED you mention.

3) I'll check this out.

Many thanks, I've got the help of my brother who is better with elec. than I. He pointed out the cold solder joint.

All the best,

Sam

Re: 4002 tonearm not lowering

yachadm — Thu, 29 Apr 2010 11:21:54 GMT

And #3 is the mechanical check - remove the squarish cover at the rear of the tone arm, and look from the rear, at the tonearm assembly.

Lift up "c", and check that the tonearm is able to move up and down freely.

You will need to balance the system afterwards anyway - also in the SM.

Menahem

Re: 4002 tonearm not lowering

yachadm — Thu, 29 Apr 2010 11:14:01 GMT

OK,

# 2 is the pivot control setup - the alignment of this is critical - if it is not aligned precisely (all other factors being OK), the arm will not drop. I always convert these to LED's, and here you can see the yellow LED. Alignment is in the Service Manual.

Re: 4002 tonearm not lowering

yachadm — Thu, 29 Apr 2010 11:06:29 GMT

Sam,

I'm puttimg up a couple of pictures - check to see that your's looks like this.

Beyond these 3 areas, you may have afaulty control PCB, nad only a proper restoration will ensure flawless operation.

This one is the LED which illuminates the slide ruler - it should not be in a plastic enclosure. Opposite it is the photo-transistor sensor.

Menahem

4002 tonearm not lowering

4decksam — Sun, 11 Apr 2010 14:34:52 GMT

Hello all,

I am a new owner of a 4002 born on: 12/14/1977 Type 5513. I have the dreaded tone arm not lowering issue.

The machine was/is in very clean condition inside. I have lubed all parts usually mentioned. The coil moves (I believe freely) however, it does not move on it's own. There is a relay tripping I assume it is for the tone arm to lower or could it be for silent mode till the tone arm hits the vinyl. I have cleaned the clear position marker and adjusted the platter hight. Speed changes for 45 or 33rpm. The up/down function does not work at all. I am not afraid to probe into this further. Where do I start checking from here?

One thing that bothers me is (I think it's) the cartrage wire leaving the arm becomes bare then insulated and bare again before it drops down through the diaphram. This cannot be normal. I have a service manual coming in the mail.

Two other things that were found when I opened the table, but I didn't know if they were part of the table. I found a threaded pin and a ball bearing.

Also it appears that there is supposed to be a bulb lit behind the position marker. I see a bulb, but it does not come on. There must be a photo sensor that picks this lite up. If this bulb does not lite will that prevent the tone arm from dropping?

New info: The bulb I thought I saw must have been the photo sensor. I unsoldered the opposing black housing and inside appears to be an led bulb. I also removed I think the tracking lamp directly under the tone/tracking arms. I noticed that the slot in the metal plate attached to the diaphram and the slot in the (must be a photo sensor below) didn't line up. so I loosened the screw holding the metal plate to the diaphram and lined up the slots. However, now the speed changes quickly to 45 and the arm does not stop at the edge of the 33 vinyl I have on the platter. I guess I don't have the two slots lined up? I know the tracking bulb lites. I do not know if the position marker Led works.

How come no one has replied? There seems to be a few good people here who have experiance on these machines

Thanks in advance for any help,

Sam