I have a beogam 6006 turntable which the arm won't come down on the record.althought the detector arm sends the signal,it just doesn't work.the arm doesn't go to it's place on its own.I have to make it travel with the forward button.How can I fix that problem?thank you in advance

Hi Chrisbou, Welcome to BeoWorld

 

Would you please clarify the symptoms because I’m not sure whether I understand them correctly.

 

If you press PLAY, does the arm not move at all

If you press <<, presumably you can move the arm to the desired spot on the disc, so the left and right manual movement controls work OK.  This means that the belt and motor are OK.

If you then press PLAY when the arm is in the right position above the disc, the arm does not lower or move at all.

 

For the third point above, do you hear a click at all when you hit the PLAY button.  Already starting to sound like a faulty coil or sticky mechanism but I'm not 100% sure.  Has this unit been operating regularly or has it been standing for a long time?

 

Thanks

 

Geoff

Thanks for replying Geoff! when I press PLAY ,the arm does move close to the edge of the record but stop short of reaching it.Then,I press forward and the arm will go over the record but the play button won't make the arm drop.I have check all of the detectors and motors and everything should work.the arm detector sends the signal correctly to the processor,when I put some voltage to the lift coil 'the arm will drop.Another thing,I can change the speed manually but it wont change when the detector arm goes over the ribs of the turntable.I'm really scratching my head!!!           When I press PLAY,no click is heard and,finally,yes it has been standing for a long time but the reason it is so is because it was making that problem.  thanks   Chris

Hi Chris

 

Thanks for the updated description of your problems, it gives me a better idea of what is going on.  I have done a lot of work on my BG6006 and managed to get it working properly but there are plenty of things that I still have to learn about this machine.

 

The first point that you have made is that when you press PLAY, the arm comes up short of the turntable.  You don’t say by how much, is it a few mm or cm?  If it is only a small distance, this is corrected by adjusting the position of the limit switch.  The manual states that the limit switch is set up by putting on a 30cm disc, determining the error in the drop position and then adjusting the position of the limit by loosening the screw and moving it to compensate.  Perhaps you could try that and at least you will have the correct starting position to work from.  Thereafter, we will have to decide what is stopping the arm from finding the right position and dropping.

 

I had some problems with the lowering mechanism recently and I tested it by giving the coil a 5v supply.  In my case, the plunger was stuck and simply wasn’t moving.  After a bit of pulling, pushing and cleaning, everything worked as it should.  It sounds as if you have also done the 5v test and your coil and lowering system is working OK. 

 

You also mentioned that you don’t hear the relay click and it is now starting to sound like the detection system is holding everything out.  The fact that the system is not picking up a record size change and altering the speed accordingly also seems to be pointing in this direction as well.  The disc detection logic terminates at P6.9 which is Pin 33 on the micro.

 

Yet you say that the detector system is working so I presume that you measured the voltages at that point.  After you reset the limit and get the arm to move to the correct starting position, do some more checks to see how the voltage changes at Pin 33.

 

I must admit that I am starting to get confused myself.  If the detector is happy and the arm is in the right position and the drop mechanics are working and you get 5v at the coil ….. everything should be OK.  I’ll have to think about what else could possibly be causing your problem.  Next time I open up my unit, I’ll check to see what is happening in the detector circuit during these different situations and try to verify the logic.

 

Hope that this has helped a bit

 

Geoff

Tonearm stops just short of the record = clean and lubricate the threaded shaft and replace the servo motor belt.

It's a matter of friction as the tonearms are slowed down to get to the exact starting point and this is where the mechanics will have to work precisely and without slippage. The arm won't lower until the correct number of pulses from the opto sensor has been counted.

Martin

Hi Martin

I had wondered about the belt slipping option but this did not appear to be an issue because the arm can be moved to any position using the manual button.  If you get a small amount of slipping, what stops the motor doing a few extra revs to compensate?  Does the motor continue driving until the opto sensor reaches the correct amount of revs or does it time out?  I would be interested to understand what condition causes this process to stop.

Thanks for your help

Geoff

Thanks to both of you guys!

I just cleaned the threaded rod and lubricated everything but the problem persists.The belt,althought not the triangular type seems to be fine as there  is no slippage at all and no dragging.Could it be the problem anyway?Since we last corresponded I changed the 0ic1 5 volt regulator cause it was giving 4.8 volt so I thought maybe it had something to do with it but no.

yes Geoff,I did check ai pin p6.9 and then decided to check at  pin 33 of the IC itself and  it's ok.

I also checked every detector to see if they were giving the right signal and...everyone do(or does?)

For the question you asked Geoff,when I press PLAY,the arm moves about 3 cm then stops.If i bring the arm with the forward button to about halfway to the record and then unplug the turntable,when I plug it back,the arm will return toward the right again for only 3 cm.If I want to go all the way,I have to use the return arrow.

If I press the TURN button,(at the stop position),the motor will turn to the speed I want and if I press STOP,it will stop.However,if I press PLAY and then press STOP then it won't react at all.now the funny thing about this whole thing is that I have TWO such machine with exactly the same problem and yes,Idid turn of my benchlamp before trying anything else.

I'M REALLY PUZZLED!!!

thanks again for all your help.I appreciate it.

Chris.

 

I can't believe that you have two machines which are both playing up to that extent!!  Are you sure that the voltage supply to your house is not rediculously low for some funny reason.

I have checked the stroke and the speed of the arm during the initial movement and come up with the following information which is the same on both my BG6006 and BG8002.  The travel distance is 46mm and it completes this in ±2.0 secs.  I would be interested to know if your initial travel is being limited to 30mm and how long is it taking to do this.  If your short distance is also taking around 2 seconds then I would have to agree that slipping and sticking are likely issues.  If the speed is correct and it is covering the 30mm in 1 to 1.5 secs, then the arm appears to be coming up against a stop somewhere.  Maybe the motor is not performing properly and running slow???  --but two of them at the same time???

The plot thickens!!

Geoff

When the tonearm halts, try removing the belt without disturbing the position of the opto interrupter and watch the motor. If it rotates, the tonearm carriage doesn't move freely enough. Clean the threaded shaft and the nylon bushing under the carriage. Add a little fresh silicone grease and it'll be fine.

These Beograms count pulses, it's not timed. If the correct number of pulses can't be reached, it won't lower. 

Martin

I have a Beogram 4002 type 5511 and encounter some problems maybe you guys here can help/advise me.

 

 1) after the arm drop down to play LP, it will just static, so the music is keep repeating at the same position.

2) left channel no sound or extremely low volume

Any advice on this? 

 

The motor (for the arm) can move by pressing >> or <<

 

 

Hi Martin!

I removed and cleaned the threaded rod with a degreaser and a toothbrush then I put everything back in place and the arm does move a little further(about 2 mm)but I still have the problem.I decided to try the same experiment with the arm removed leaving only the threaded rod.The result is the same so the carriage is not dragging.By the way,I did try to remove the belt as you said and the motor does run but very slowly and weakly.

I checked the voltage on the tangential motor and when I press PLAY,it is 8,2volts.Is it enough? I'm thinking of trying some other belt size althought it seems adequate just to see the effect.

I'm not giving up!

Bye and thanks!

chris.

wongss; Sounds like the optical tracking sensor (at the base of the carriage) is faulty, probably a burned lamp - or the interrupter is badly adjusted.

chrisbou; Sounds like you are closing in on the problem. The voltage seems fine and the slow rotation of the motor to get the carriage to the exact drop spot is correct, we just have to get the threaded rod to follow the slow rotation which is where seized up things turn up. Take out the rod and clean at both ends where it rests in its plastic holders. Dust off the opto elements while in there.

Martin

Hi Chris 

Never give up, all it takes is lots of time!!  I have checked the voltage on the motor when it is going to the start position and it seems to be between 8 and 9volts.  Looks as if your motor is doing its job.  So if you are happy that the initial park position is OK and the motor is able to reach the correct speed, it might be time to look at the setup of the pulse counter.  Is your fully intact? I had a problem where the plastic arm was cracked and this left the board floating quite a lot.  I had to make a spring arm to keep it in its proper position.

Keep at it

Geoff 

Hi!

Is the optical tracking sensor the one that detects the small movement of the needle at the base of the carriage?If so,when I made the arm drop by putting 5 volts on the coil,the arm motor was running slowly and doing what it is suppose to do.The light works fine.It's funny that the carriage would advance slowly if I make the arm drop but refuses to do so after the initial few seconds when it reaches the disc. 

As for the rod,I have cleaned up everything including both ends.I still didn't put the carriage back on the rod.I wan't it to be free wheeling and the rod is very easy to turn with no drag at all but I still have the problem.I didn't get a chance to try a new belt yet but I plan to do so tomorrow.

And yes Geoff,everything is fully intact.I did inspect the underside of the carriage to check for cracks or anything odd but everything is perfectly fine.

chris

 

Dear Martin,

 The lamp is working....

Hello!

I changed the belt and there are some improvements.The carriage now reaches the disc exactly where it should but then,it starts to very slowly back up about a millimeter or two and the arm doesn't want to drop even if I make it travel to the middle of the disc.No clicks either.Should I put some grease on the threaded rod also?I put some on each end.

thanks again for all your support.

Chris

Hi Chris

Glad to hear that you are making progress.  The manual asks you to put some lubricant at five spots on the spindle and the in their case, they seem to use a mixture of two products to develop an oily consistency.  Since I have no experience with the lubricants that they quote, I simple put a drop of light machine oil at a few places down the spindle and it seems to work OK.  Others may have a different idea.

Does the motor actually go into reverse when the arm backs up or is it just releasing some compression in the system?  When it reaches the park position over the disc, are you getting any change in the coil voltage at all?

Geoff

 

Hi Geoff

Yes,the motor goes into reverse very slowly and when it stops,there is no change in the coil voltage.It takes about 30 seconds for the arm to back up at total stop.

I'll try lubricating at the other point see what it does.

I'll keep you posted!

thanks again

chris

Check the adjustments of the << and >> keys. It's mentioned in the service manual and is just about the only thing that can cause this fault.

Martin

I CAN'T BELIEVE IT! IT WORKS!!

Thank you again for all your support.I've been repairing electronics for twenty years but I have to say that I never could have don this without you.

If you have time,I wish you can explain to me why the adjustment of the keys solved the last problem.I know the belt and the cleaning of the rod cured a part of it but the adjustment would not have been one of my choices for sure.

thanks again Martin & Geoff

chris

 

You can simulate the fault by holding the >> button slightly depressed while starting the Beogram.

The slightest touch of the button will raise the tonearm (or keep it from lowering at startup) and have the carriage moving slowly to the right.

Good job ! 

Martin

Hi Chris

I have just come back from an overseas visit and have been catching up on all of the news.  Glad to see that you have finally had some success, as usual it makes all of the hard work worth while.  I must admit that I would never have related your problem to the operation of those two keys.  I have set up the voltages on them several times but usually after the bulbs have blown.  Would you be able to clarify whether the voltages that you found to be incorrect were too high or too low and by roughly how much?

Well done again

Geoff

Welcome back Geoff!

The voltages were a little to high but not by much,maybe up to 1 volt.On either the forward or the rewind button(sorry,I don't remember which)even when I ajusted the voltage,it was still a bit(about 800mv or so) high but worked anyway.

On the other side,I could adjust it higher or lower than needed.I didn't want to take the switch apart since it worked anyway.

Lack of time or lazyness maybe.Probably the latter.

Thanks again for your help.

Chris