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Hello everyone,
I have a Beogram 4002 (type 5513) that I started repairing around 3 years ago. I have been able to fix all the issues with it thus far, but I have come across one that has me completely stumped.
So far, I've lubricated the platter motor bearings, replaced both belts, replaced the tracking sensor light with Beolover's replacement assembly and calibrated the tracking through that. I have also calibrated the counterweight and the tracking force.
The problem is that when starting to play a record, the stylus will drop on the first groove and sit there skipping over and over to the start. Peering into the cartridge I can see the stylus moving back and forth in the groove laterally, but the stylus is not moving the tonearm with it in order to activate the carriage motor with the light sensor.
I know that the photo sensor system is working properly as when I have the platter and record removed, I am able to start "playing" and manually move the tonearm to activate the carriage movement. I have tried every possible tracking force and combination of the counterweight position.
My best guess is that the tone arm is not pivoting freely enough in the left direction to allow the stylus to bring it along with it. I tried to use some Singer sewing machine oil to where I believe the pivot is, but that did not have any effect. It could be something else entirely, but I'd like to know the best way to access the pivot and lubricate it properly.
Any help or information would be greatly appreciated.
Have you verified the tracking force is correct? Start with at least 1.2 grams and check it with a scale. I have seen tracking issues when the tracking force is set too low for the cartridge.In testing the tangential drive a coarse check can be made as you performed it without the platter and manually moving the arm. However, that only gets you in the ballpark. You need to use a vinyl record on the platter with the belt removed. Per the service manual set the arm down more in the center of the record (although I often try several tracks). Manually rotate the record by hand, counting the revolutions and watching for the tangential drive motor to advance. It should advance within two to four revolutions initially then every revolution after that. If it is not advancing then adjust the tracking sensor position. If your adjustment takes you to the limit of the adjustment (eccentric) screw and your tracking is still not correctly adjusted, then you might have to loosen the position of the sensor assembly on the pivot arm...so that you are somewhere in the middle of the range. You want some room for fine adjustment tuning later. Of course Beolover's replacement sensor lamp assembly also has a trimmer for really fine tuning. It adjusts the brightness of the light source.
When the platter is not installed and the tonearm lowered do you feel resistance when you try moving the arm by hand? It should move freely.
A couple of other things to double-check - Is the tangential drive motor secure and not wobbly? Is the belt on it correct and not slipping? The reason I ask about the drive motor being wobbly is that I have seen the foam damping material inside the black, plastic housing disintegrate into dust a couple of times leaving nothing to hold the actual motor securely. That isn't very common but something I have seen.
Don't over lubricate things. The Beogram doesn't require much lubrication. Unrelated to your tonearm tracking problem, when you mentioned lubricating the platter motor bearings you were referring to infusing the two bearings the way Beolover does it right? Just making sure :-).
-sonavor
Hi
If you manually move the Tonearm to the Left, how is the Angle to the Sensorarm when the Spindlemotor strarts to work?
Maybe you have adjusted the lowering Limit of the Tonearm too high above the Platterribs so the Linkagearm in the Back of the Tonearm is stucked in the V Shaped Liftmechanism.
Here is a Link to Beolovers Site . with a Video how to Adjust the Lowering Limit:
https://beolover.blogspot.com/2015/11/beogram-4002-4004-adjusting-tonearm-lowering-limit.html
I hope that helps to find a Solution.
Best Regards
Christian
Does the needle actually touch the record?Is the tracking force set correctly?Is the needle OK?
Martin
Spassmaker: Hi If you manually move the Tonearm to the Left, how is the Angle to the Sensorarm when the Spindlemotor strarts to work? Maybe you have adjusted the lowering Limit of the Tonearm too high above the Platterribs so the Linkagearm in the Back of the Tonearm is stucked in the V Shaped Liftmechanism. Here is a Link to Beolovers Site . with a Video how to Adjust the Lowering Limit: https://beolover.blogspot.com/2015/11/beogram-4002-4004-adjusting-tonearm-lowering-limit.html I hope that helps to find a Solution. Best Regards Christian
Thank you for your reply,
When manually moving the tonearm to the left, there is only a very slight change in angle needed to activate the spindle motor. This has led me to believe there is no issue with the photosensor positioning. However, it does take a somewhat significant amount of pressure to change the angle the tonearm is at (it is in the lowered position.)
I followed Beolover's tutorial on adjusting the lowering limit and adjusted accordingly. When the tonearm is lowered, there is no contact with the v shaped piece so I believe it is not rubbing and preventing movement.
Thank you,
Garrett
Dillen: Does the needle actually touch the record?Is the tracking force set correctly?Is the needle OK? Martin
Yes, there is contact with the record. I can move the tonearm farther towards the center of the record and hear a short amount of music before the needle skips back to the beginning of the groove.
The tracking force is currently set at 1 gram with my MMC 4000. I have experimented with every tracking force possible to no avail, so I do not believe this is the issue.
I actually have two MMC 4000's, one of which is slightly dulled but still usable and the other which is in very good condition. The dulled one I have been doing the majority of my testing with to make sure I do not damage my cartridge that is in better condition. I first noticed the issue on the good cartridge. The issue occurs on both cartridges even after the various adjustments that I have made. With both of them you can see the small arm inside the cartridge following the groove and then skipping as it fails to bring the tonearm along with it.
sonavor: Have you verified the tracking force is correct? Start with at least 1.2 grams and check it with a scale. I have seen tracking issues when the tracking force is set too low for the cartridge.In testing the tangential drive a coarse check can be made as you performed it without the platter and manually moving the arm. However, that only gets you in the ballpark. You need to use a vinyl record on the platter with the belt removed. Per the service manual set the arm down more in the center of the record (although I often try several tracks). Manually rotate the record by hand, counting the revolutions and watching for the tangential drive motor to advance. It should advance within two to four revolutions initially then every revolution after that. If it is not advancing then adjust the tracking sensor position. If your adjustment takes you to the limit of the adjustment (eccentric) screw and your tracking is still not correctly adjusted, then you might have to loosen the position of the sensor assembly on the pivot arm...so that you are somewhere in the middle of the range. You want some room for fine adjustment tuning later. Of course Beolover's replacement sensor lamp assembly also has a trimmer for really fine tuning. It adjusts the brightness of the light source. When the platter is not installed and the tonearm lowered do you feel resistance when you try moving the arm by hand? It should move freely. A couple of other things to double-check - Is the tangential drive motor secure and not wobbly? Is the belt on it correct and not slipping? The reason I ask about the drive motor being wobbly is that I have seen the foam damping material inside the black, plastic housing disintegrate into dust a couple of times leaving nothing to hold the actual motor securely. That isn't very common but something I have seen. Don't over lubricate things. The Beogram doesn't require much lubrication. Unrelated to your tonearm tracking problem, when you mentioned lubricating the platter motor bearings you were referring to infusing the two bearings the way Beolover does it right? Just making sure :-). -sonavor
Hi,
I do not in fact have a scale with the proper precision for this, but using the scale tool included with the cartridge I was able to determine that 1 gram is around 1.1 grams on the adjustment dial. I have incrementally tested it from 0.5 to 1.5 grams (as read on the dial) and found that changing it did not fix the problem. FYI, whenever I made or make another adjustment with the tracking sensor I test with various tracking forces as well.
I have adjusted the tracking sensor to the point where the carriage will begin moving even while the tonearm is parallel to the sensor arm. I then adjusted back in very small increments. Manually spinning a record with the arm down causes no movement in the tonearm whatsoever for it to activate the tracking sensor. Looking inside the cartridge you can see the cantilever moving to the left and then skipping back when it no longer can track the groove as the tonearm is not moving with it.
There is a slight resistance when moving the arm by hand. Once at an angle to the left, it is stiff enough that it will hold the angle and is not freely swinging. This is all of course with the solenoid engaged and there being no contact between the v-shaped groove and the bit that sits inside it. I feel like this is the problem but I am not sure how loose or stiff it should be normally.
There is no wobble to the motor and the belt is secure. Using the left and right movement keys works fine and the tangential movement using the motor seems to be smooth.
Yes! I did follow Beolovers method and am very pleased, no issues to report a year and a half after doing it.
Hi Garrett
What I´ve already seen on a MMC 3 to 5 that the Needle skips back and force when the Suspension of the Pickup is broken. The Tonearm doest move at all with a broken Suspension.
The Cantilever jumps in random Direction left and right.
I´ve never seen a broken Suspension on a MMC 20 or MMC 4000 and so on.
If you touch the Cantilever very very genttly with a Toothpick, does it always go back in it´s old position?
If it´s "snapping" to random Points the Suspension broken.
But once more, I´ve never had a broken Suspension on these Cartridges, and both Cartridges with a broken Suspension??? I don´t think so.
There must be something else going Nuts with the Tonearm.
Don´t give up, I´m shure sooner or later the scales will fall from your eyes and you ask yourself: Oh dear why didn´t I saw this?
Chrischi
Hi Garrett,
You certainly have an odd case. One I haven't encountered before. Having set the sensitivity so high where the arm will advance itself indicates the motor responds to the sensor.As the next step you mentioned manually spinning a record with the stylus in the groove.However, prior to that did you try back off the sensitivity slightly where the arm no longer advances by itself? ...and at that point can you make it advance by gently moving the tonearm? If it doesn't advance the arm by doing that then possibly the sensor itself needs replacing. By that I mean if it only can be adjusted where it is too sensitive and moves by itself or never moves.If it can be adjusted where different amounts of (manually applied) pressure on the arm will cause the motor to advance then I would say the sensor is probably okay. How secure is the bracket that attaches the aperture to the tonearm pivot base? Is it staying in place?
Of course another possible problem is that the voltage the sensor is producing is too low. That could also be due to a failing sensor.You should be able to test and check out the responsiveness of the sensor commanding the advance motor prior to doing the steps where you are manually turning the platter with a test record. So if you can pass the sensitivity tests with the arm hanging out there without a platter but then the tests with an actual record fail I would guess the problem is mechanical where the tonearm is not pivoting.
I have found the source of the problem! The interruptor (the little piece of metal that obstructs the light and moves with the arm) was too low and was in contact with the black plastic piece that covers the sensor. This was creating a large amount of friction for the entire tonearm movement. I loosened the retaining screw and shifted the entire thing up slightly.
Some minor adjustment of everything and now everything works perfectly! No skipping or any other issues to report.
Thank you all for your help. Maybe this thread will help someone else as well. ;)
Okay, that makes perfect sense. I should have listed that on my last suggestion :-).There is a note in the service manual regarding the height of the moving aperture from the base.
Nice work finding the problem.That is the good thing about those Beogram 400x turntables. The electronic components are not exotic and there are a lot of mechanical things where an owner should always be able to keep them in good working order. I love the Beogram 800x turntables too but if something happens to the proprietary processor IC they are dead. Luckily those ICs have been quite durable and reliable but that is still a worry that doesn't exist with the BG400x series.
I am new to the forum. Can you send couple pictures of the interrupter location on the tonearm. My email: chiupc@yahoo.com
Thank you!
Do you have a copy of the Beogram service manual? If not you can download it from the Beoworld Forum with a Silver or Gold membership level.There is not really a part named "interrupter".The service manual calls it the Diaphragm. I often refer to slot in that piece as the aperture. It controls how much light from the lamp reaches the sensor.That amount needs to be calibrated per the service manual. The position of the Diaphragm is critical to the Beogram record tracking working correctly.The Diaphragm should be 1mm above the sensor.I will see if I have a photo that points to the parts.
Here is a photo.
The Diaphragm needs to be 1mm above the Tracking Sensor Housing. It can't rub against it.Be very careful in making any adjustments with these components. Changing any of the component positions will require re-calibrating the Beogram record tracking.
Fantastic, you are the man. Thank you so much!
Try to adjust the sensor today but having difficult time get it to operate properly. Do you have any suggestion on how best to accomplish this?
Greatly appreciate any advice.
Sensor = diaphragm position.
gmacro: Hello everyone, I have a Beogram 4002 (type 5513) that I started repairing around 3 years ago. I have been able to fix all the issues with it thus far, but I have come across one that has me completely stumped. So far, I've lubricated the platter motor bearings, replaced both belts, replaced the tracking sensor light with Beolover's replacement assembly and calibrated the tracking through that. I have also calibrated the counterweight and the tracking force. The problem is that when starting to play a record, the stylus will drop on the first groove and sit there skipping over and over to the start. Peering into the cartridge I can see the stylus moving back and forth in the groove laterally, but the stylus is not moving the tonearm with it in order to activate the carriage motor with the light sensor. I know that the photo sensor system is working properly as when I have the platter and record removed, I am able to start "playing" and manually move the tonearm to activate the carriage movement. I have tried every possible tracking force and combination of the counterweight position. My best guess is that the tone arm is not pivoting freely enough in the left direction to allow the stylus to bring it along with it. I tried to use some Singer sewing machine oil to where I believe the pivot is, but that did not have any effect. It could be something else entirely, but I'd like to know the best way to access the pivot and lubricate it properly. Any help or information would be greatly appreciated.
I trust that when you say that you lubricated the platter motor bearings that you followed the method that Beolover demonstrated in his restoration video on that?
The tonearm pivot shouldn't require any oil.
In your stated manual test do you mean that you let the tonearm lower, then nudged the arm to the left and observed the servo motor begin to advance the arm?
Without the platter in place you should be able to do that nudge test and see if your tracking sensitivity is way off or if it is close.
If you cannot nudge the arm on the other hand...then do look for some obstruction to the arm.Note that the lateral movement of the tonearm isn't much and doesn't need to be.If there are obstruction issues then check these things:1. Is the diaphragm plate too low and rubbing on the top of the sensor housing?2. Is the tonearm counterweight to close to the back of the arm and preventing proper movement?3. Is the bracket that connects to tonearm to the raise/lowering lever interfering when the arm should be in record play position?
I posted a couple of things to try but the post is waiting approval.
I finally got it to work properly after I read the service manual. Thanks for all the help.
Time to order a new cartridge from Soudsmith. Do you have any recommendations?
I’ve had an SMMC20EN for ten years and I’m happy with it.
Jacques