Got the BG running, with all lights, 33, 45, and tracking sensor, the tangential drive is working, the fly wheel was bend, but now straight, running within 0.1 mm both dimensions, running free without band.

With a 45 disk on the fly wheel, without the aluminum platter, I press start and have to help by turning the wheel by hand, until the mecanical movement finish, then the drive motor is able to turn the wheel by itself, but very slow, some half speed I guess.

adding the aluminum platter, the motor dont turn at all. On 33 rpm the motor moves a little when pressing start (1/8 turn) and then stops.

I checked the current to the motor on the main PCB jack 5 (P5): with 45 rpm P5-1: 11.25 V, on P5-3: 9.73 V, on P5-4: 10.18 V, on P5-5: 0.1 V.

With 33 rpm: P5-1: 11.28 V, P5-3: 7.94 V, P5-4: 8.54 V, P5-5: 0.05 V, with 45 the motor is turning (slowly) with 33 its not.

On the the motor there is a small PCB with caps and resistors on it, these are not shown in the drawings.

Anybody had this problem ?? is it motor or the small PCB.

Pics

Wow, these motors are the same as the ones found on cassette decks, Panasonic FG servo, very likely busted. The brushes are metal and have a tendency to disintegrate!

How did you fix your sub-platter?

chartz:

Wow, these motors are the same as the ones found on cassette decks, Panasonic FG servo, very likely busted. The brushes are metal and have a tendency to disintegrate!

How did you fix your sub-platter?

Here the link, will try to open the motor, pain in the but.

http://forum.beoworld.org/forums/p/35928/298970.aspx#298970

nothing wrong with the motor, but the motor control board is bad, and no diagrams what so ever anywhere, I've been surfing the web for hours and nothing, its a small print but I need the values of the caps and whatever.

And you can't find it in the service manual here on the site?

-Loudspeaker

On all diagrams for BG 6500 and other types with the same motor, the motor print is white land, nothing, I've surfed the forum, internet and my wifes shoe boxes, nothing, on the web I find a lot of FG servo for tecnics TT but no motor print. The same motor is used in a lot of CDs and dig. printers, but I do not need a motor, the motor is OK, the problem is the PCB, Dillen is is looking for something in his secret chamber. If he does'nt find anything, I will have to start changing everything, piece by piece, which means that I will have to build something to test outside the TT. I am convinced that a lot of motors has been changed with PCB because of this problem, but I want to get to the ground of the problem, for future use here on the forum. I've been working 3 days on this and I wont give up ever.

I found a motor of the correct type.
The bearings and/or commutator are worn out on this one I think but the board looks fine.
PM to you.

Martin

Thanks Martin you are my favorit Beofessor, and I love your secret chamber

Thank you.

Got my spares from Martin yesterday, 4 drivers for the RL 140s and a lot of caps for the rest, ofcourse I had to start emidiately and the first thing was the crossover from one RL, changing the caps is easier than I thought, both crossovers was finished in 40 min. and its the first time I do it.

I assambled one RL and connected it to a 20 year old Sony reciever/amp, 2 x 10 wats, FM station and sound came out, sounded OK. Before I started the repair I tested with the same Sony and it was bad, distortions and with volume at max. the RLs did'nt play as loud as the original crab Sony speakers.

Today I assambled the other RL and connected both, there was a differens in the middle tones between the speakers, distortion in one speaker, audible even for me, my ears are old and tired, I started checking and saw one string of Rockwool insulation hiding in one corner of my garage, that string goes into the bucket where the middle tone driver is located, so open up again, add the rockwool string, connect again, and bingo, same sound in both, good sound even with this bad amp. and now louder and much better than the old Sony ones, I'm happy.

As I bought the drivers from Martin I have to give him some roses, these drivers are better than new, check the pic below, there is no signs of glue rests anywhere, the new surround fits perfectly and the drivers looks better than the original.

PICS

Martins Driver

Crossover before

Old caps out

New caps inn

Ready to assamble, here I forgot to put in the insulation in the bucket, amazing what this little detail do to the sound.

Got my spare motor from Martin today, will later today try to figure out why the old one doesnt work, the motor runs when connected directly, but there is something wrong with the PCB attached to it.

With the motor with its PCB board I started with fresh energy on this hard headed deck. Hooked up the motor and tried it, no luck and no motor movenment, changed Martins PCB to my old motor, now same failure as before, starting. the motor gives a small move and stops, helping the platter with my hand to get over the first mec. movements, the motor is able to turn the platter slooowly on 45, on 33 nothing happens, Ive checked all resistors from IC to the pins for the motor, Ive changed a 10 K0hm trimpod but same failure, to be sure that motor and its PCB is OK/ I took the same motor from my BG 5000 and connected it to the 6500, same failure, and this motor with its PCB works like a charm on my BG 5000.

Any ideas anyone ???

Hi,

Well now you can be certain that the motor, along with its PCB is not the problem.

How does the 5V regulator look like? How about C2 (470μF)?

Do RL1 and RL2 work?

Do the speed adjusters (R32/R34) have any effect?

chartz:

Hi,

Well now you can be certain that the motor, along with its PCB is not the problem.

How does the 5V regulator look like? How about C2 (470μF)?

Do RL1 and RL2 work?

Do the speed adjusters (R32/R34) have any effect?

 

 

Will check the 5 V, C2 is new,

will check RL1/2, 

R32/34 does not have any effect when the motor is running,

R34 is new, R 34 is OK checked with Ohm meter.

Thank you Chartz appriciate your help.

Soren

RL1, RL2 is working OK,

Leg 9 on IC 5.3 V in stand by.

And all mecanics working when pressing start and turning by hand, the pick up drive working running to end of disk, lift off and return working as should.

Started again today, I got the 5.3 V on leg 9 on the IC, pressing start the motor jumps a little, by hand I help turning the platter over the start sequens, with 45 platter on. the motor starts turning slow after the start sequens, but should start emidiately after the start button is pressed, and as the start sequens involve more power to get over the mec. movement, the motor should get, I suppose, some 12 V, maybe over pin 1 in P5, or pin 3 in P5.

Pin 1 is, I think, triggered from leg 23 and/or 24 on the IC, which also triggers RL1 and RL2, but somehow the motor dont get any voltage before S1 or S2 is triggered, and after S1 or S2 is triggered the motor gets its power from leg 15 on the IC to pin 3/4 in P5.

So, do I have a problem with TR6, or is it in the circuit between leg 15 on IC and P5, or, god forbid, the IC, in hope for a little help or comments

Soren

Hi,

I'd unsolder TR6 (or, more easily, R10) and test it. Don't underestimate TR4, so test it as well (nothing to unsolder).

Also, I assume you have already tested all the connections to the motor board, and that the PCB has no cracked tracks!

Jacques, found it, a broken of piece of track where the wires are attached to the PCB with clips, even a blind man could see it, this is the third time I checked it, sorry for taking up your time for something so stupid as this, will be more throughly in the future, will post a photo later, your going to laugh your but of.

Anyway, I've learned a lot going over this deck, mostly thanks to threads from you and other members. Now onto the sound part, and if the deck will function with the remote. Will come back with more

Thank you, Jacques

Hi,

Well, hardly a surprise, amigo, considering the bad treatment you told us about before...

Excellent work then, very happy for you!

You now have a perfectly good spare motor!

Repaired the broken track with a piece of thin wire, connected everything works OK, and the Master command console works with it.

The bad news, it sounds better than my BM 2400 with BG 2404, using same MMC4 and same S45s, I will open the BM 2400 and the BG 2404 again to see what I missed there, but I think in the BM the preamp, and in the BG I will check one more time all connection.

Pic of the PCB, at buttom, in the middle on the board you see a light brown area, that where part of the board was broken away, there is 4 tracks in that area and the track going from R32 to pin 3 on P5, was broken away with the piece of board, sorry for the bad pic, its from my phone

Here the BG 6500, playing Gloria Gaynor, Experience, from 1975

One more with the 33 light on

I'm Happy, Thanks Jacques, Thanks Martin, And I have here a good motor PCB with a bad motor if anyone needs.

Now onto the Beocord 6500, and the system is complete.