ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I left a post in the north America forum and did not get much response so I figured maybe someone in this forum would know.
Screw G in the photo - Seems to be a Cam type screw with a spring rod above it. This cam does seem to lower or raise the tone arm height. It also seemed to change the horizontal position. I am not sure if that spring needs to be below it or above it.
A & C - Screws simply hold the Sensor arm on. If you take them out you can remove the sensor arm. It still has wires hooked to it. Did not see a way to unplug them. The holes are large enough where you can move it side to side to get it straight. The sensor seems to be motion controlled, just moving the tone arm closer to it will cause it to auto lift arm.
B - Brass front screw on sensor. Does nothing, maybe holds metal part to plastic insert. Manual says its an adjustment
D - Counter weight. Do not ever change this. Its set from factory. Can verify weight using a shure cartridge scale. Usually can use plastic slider to compensate. Measuring is tough as have to have unit turned on to lower the arm, and the platter spins when its on in down position. Makes it tricky to get the scale on the table.
F - again no need to adjust, but it tilts/rotates the tone arm clockwise or counterclockwise a small amount.
E - Probably Tone arm mount screw
To me the unknowns are G and the spring clip above the screw. In off position I can move the tone arm over and actually above the Sensor arm using my fingers. I can't do that on my other 8002, it seems to resist any vertical movement. So something is out of place but not sure what.
When I lift the tone arm you can see brass cam screw G moving down. I am wondering if screw G were above that rod (seen in the pic) it would prevent the tone arm from being so sloppy in off position.
Like I said on AK: given the shipping stress, the first thing to try (and 90% likely to fix) is to loosen "E" slightly and see if the there's enough play to relocate it to parallel to the sensor arm.
There is 2-3* of slop in the mounting around the screw hole; the reverse of this is most likely cause of why it is not parallel to the sensor arm since being trashed in shipping.
Regards, Phil
PS: yes, "G" moves the brass thimble laterally and the shiny steel thing raises the tonearm when it moves down into the "V: of the thimble (which is how you see it; it is only lifted and not touching when the arm is released by it to commence "play"
When you turn "G: it will move the up station of the tonearm closer or farther from the sensor arm.
If the arm is NOT parallel to the sensor arm while tracking a groove, and the arm can be reset at "E" adjusting "G" will be counterproductive and and require several secondary steps to restore things.
It's similar to having a well aligned suspension on your car with the steering wheel centered (when going straight), and someone pulls the steering wheel off and turns it 30*. You could get it centered again by realigning the suspension, and it will drive OK, but it won't be 100% correct-and all that was needed was to put the steering wheel back to where it belonged relative to the steering gear.
I don't go to AK anymore so don't remember your posts. This is a different table than that one. I fixed the other one. This is my second 8002. I have it playing and the sensor is arm is perfect.
The only issue I have is the slop in the tone arm. Its very loose feeling vs my other 8002. I can lift it up and move it over the sensor arm with no resistance. It does play but something is not correct as it bounces some on lift off. Its functional now just the tone arm is missing a spring or is adjusted wrong. Thanks for the help on the Sensor arm. That one was pretty easy to fix. The tone arm is a little tricky as I can't see exactly how its put together.
The previous owner admitted to messing around with G in attempt to put more weight on the tonearm. So no idea what is factory set for it. Its a cam type screw in which it moves the tone arm up and down. But it also seemed to change the horizontal positions as well.
Main issue now is how sloppy the tone arm feels, no tension on it when you move it side to side. During play I am not sure this is a big issue as it does seem to track ok. It just pops a wheelie when I press off and teeter totters a bit. I'm not understanding how the the tension works on it. I'll have to dismantle my other one to compare.
RAJOD: The previous owner admitted to messing around with G in attempt to put more weight on the tonearm. So no idea what is factory set for it. Its a cam type screw in which it moves the tone arm up and down. But it also seemed to change the horizontal positions as well.
It's a little tricky talking about the adjustment screws as your labels in your diagrams are not labeled with the same characters as the service manual. So, using your designators, I think you will have to get your tonearm back to where just "E" (B in Pick-up Arm Balancing in the manual) manages the arm balance. If "G" (B in Vertical Parallelism of the Pick-up Arm in the manual) has been moved to try and add more weight, then you may have to adjust it to get the Pick-up Arm Balancing procedure back to normal. Because all of those adjustments can affect each other, it will take a lot of patience. I don't know if doing that will fix the sloppiness of the tonearm though. If the previous owner moved things too far something may have got way out of position or even broken. I checked the tonearm on my BG8002 units - when I manually move the arm to the left or right (with power off), and let go, the arm snaps right back to its proper position. On your 8002 with the problem, does it not return back to center on its own? Or are you saying that the resistance you feel when you move the arm just feels weak?
I made my labels before I looked at the service manual. If I could edit my posts I would fix it to prevent the confusion. sorry :(
Yes when He moved the counter weight I wonder if he lifted the arm too high and something snapped. Its very difficult to work on those arms with the lid in the way and would not be hard to do that.
Yes you are correct on the sloppyness. There really is no resistance when I move the arm. I can move it like 1 inch higher than sensor arm and left or right. It very slowly will move towards center if you let go but its not a snap back like it should be.
It does not seem to affect playback as a tone arm should be loose and resistance free during playback.
I just wish I understood how its suppose to be and what is causing the issue.
I will probably have to tear my good 8002 down and compare them side by side. But there is always the risk that I break one doing that. So I am a bit reluctant to do that since they both work now.
sonavor,
Thanks for the help.
When you attempted to lift your 8002 tonearm where you able to view screw G at the same time. On my 8002 with the sloppy arm I can see screw G moving with the tone arm and when it hits that round steel rod above it will stop. But Im like a inch over the sensor arm. If I could somehow make that rod closer to the G screw it would not move up at all.
I went with what I thought was most important to get it working .
1. Proper tone arm weight 1-1.2 grams. This was harder than one might think as you need power to turntable to drop the arm. When it loses power the arm pops back up. And the turn table is spinning at same time. Very tricky to get my Shure tone arm balance in there to measure the weight. It was set for 4 grams not 1.2. Ive have it pretty close to 1.0 now.
2. Have sensor arm 90 degress or tangent to the platter. I did it viewing top silver top as it has a nice straight edge.
3. Have tone arm parallel with sensor arm during play. Screw G seemed to help with this. I did not need to loosen the tone arm screw for this.
4. Proper set down and lift off at end of record. This works.
So it all is good but the sloppy arm which for now is acceptable.
My other 8002 will on occasion drop a channel. Seems to be related to how long my system has been powered on. The longer its on the less likely it will drop a channel. I thought it might be the amp but when changing to my CD player the channels are fine. So its either the cart, or possibly the amps phono section.
RAJOD: I will probably have to tear my good 8002 down and compare them side by side. But there is always the risk that I break one doing that. So I am a bit reluctant to do that since they both work now.
I wouldn't do that. Don't risk a good working one to fix the broken one. If anything, just carefully disassemble the broken one (taking good pictures every step of the way).
Also, in the service manual regarding the tonearm adjustments, at the start of the adjustments it says: For some adjustments it is necessary to be able to operate the record player with a stationary turntable. The stationary state is obtained by disconnecting the mains voltage, removing P4 and reconnecting the mains voltage.
That is talking about the P4 connector to the main board in the Beogram 8002. Have you put the Beogram 8002 in the service position before? You have to be really careful in doing that. The leaf springs have to be disconnected and the whole turntable sled has to be shifted when tilting the cover out of the way (in order to clear the tonearm and detector arm). Otherwise, the arms could get damaged my the Beogram's own lid. There are pictures on my Beogram 8002 project where it shows the turntable fully opened up. However, as I mentioned before, I have never taken the plunge to dive into the 8002 tonearm assembly.
I think I figured out the cause of the floppy tone arm on my second 8002. Its missing a part. Below is a side by side photo of the good tone arm and the floppy one on the right. The floppy arm seems to be missing a spring metal clip. Also the large brass adjustment screw has a large gap between a tension rod above it.
Anyone know where I could get that part?
Good work.
From the service manual exploded view of the arm assemblies, it looks like the spring clip is Spring 0525. In the picture of the gap between the rod and screw, is the rod part of Spring 0518? Is the brass adjustment screw (next to the rod) item 0508 in the exploded view?
It makes me wonder if other internal parts are missing.
the missing spring-clip will probably cure all of your "loose-up" complaint.
The screw directly under the tonearm carriage and head-down is the stop the counterweight hits; it controls how high/low the arm goes in the up position.
I'd post some pictures but my files are too big and I'm lazy!
I think I see the reason your chrome pin above brass double-coned "G" screw rides so high (and probably doesn't "rule" the at rest up position of the tonearm (which will become clear when the spring-clip is installed): if you're in the "repair position", or have removed the upper case of the unit, un-clip the two ~1/4" OD chrome rods the tonearm-carriage tracks along, and flip it over backwards, taking care not to stress the ribbon-wire. If you jiggle the tonearm in it's up/down axis, you'll see the black plastic arm that has the chrome pin protruding from it that rides in "G". Looking at the overturned arm assy, you can easily stroke the end of this arm with your finger and see how it moves; at the very bottom end,(nearest with it upside-down) it has a cut-away that engages the plunger of the lifting solenoid/damper device.
There is a stationary protruding chrome rod that the plastic plunger (actuating part) slides on in and out of the solenoid. The end of the plunger fits inside the end of the larger arm that acts on "G" like a slice of toast in a toaster. If it has escaped from the "toaster" slot and turned 90*, it will still function, but will not fully engage the pin into the groove @G because it now has limited travel, having lost ~6mm at the actuator of the solenoid. (~6mm is the size of the plastic slice of "toast" now trying to enter the slot sideways!) You can push the solenoid in and pull the arm back and now reset it, but know that the solenoid wires are part of this moving assy so you don't want to rotate the plunger but once, and in the right direction! Looking at the overturned arm assy from the back: the plastic "slice" should be to the left of the rod it slides on; this orients the pair of wires that operate the solenoid so they are in the "window" opening where they emerge and attach to the ribbon-wire circuit board.
You might just let this go if it's working OK; this is PITA work: opening these units all the way up, you will often break various plastic clips that have hardened (at the keyboard and the rear cover, etc) and there is always the possibility of damaging the wiring to the solenoid, etc. Additionally, you will discover ways to destroy things that you never imagined until you'd done it twice!
PM me your info and I can mail you the clip.
Thanks so much for the detailed walk through. I wish you would get unlazy and post those nice photos you have. I would really like to see what you are talking about. Maybe Email me them and I'll resize them to fit.
Yes its one of the projects I want to keep on the back burner. I gave the table to my son and he keeps finding little issues for me to fix. The sloppy arm does affect it a little bit on play in the form of early record lift offs. I was able to get that fixed up better last night.
You have a spare clip? That would be fantastic.
So Rajod, I've been meaning to ask you -Is your collecting of turntables due to you returning to vinyl or are you one that never left playing vinyl? -Sonavor
My 17 YO son bought 5 records around 6 months ago. He brought them home and I asked him how he expected to play them. I had given away all my old stereo equipment. That is when the quest began. We shop record stores go to concerts etc. So something we can do together its fun. I figured If i'm going vinyl I am going retro too. So a collection of working and non working turn tables. We have two full working stereo systems with many back ups.
Plan to clean out some of the backups with a local vinyl store that sells older equipment.
These are the photos Phil was nice enough to send me. They appear to be the underside of the tone arm. I've labeled a few areas A and B. I am not sure what A does. B appears to be what I was calling a cam screw.
Very cool. For those of us that like vintage equipment and tinker with broken things to get them working again, this is a nice hobby.
The first pic shows the black/plastic solenoid plunger and the shiny steel shaft it slides along; it is the "slice of bread"(including the steel shaft) that occupies the open end of the inverted "L" shaped arm lifter.
3rd pic: The L shaped lifter part is mounted to and hangs from a pin that is seen protruding from the brass bracket in the 3rd pic; this is at the outer end of the short leg of the "L", and there's a flat, chrome U spring wrapped around it which pushes gently down on the L piece. The blackness on either side of the chrome spring is the black plastic L; above all is it's reflection on the underside of the sensor arm.
When tonearm set-down is commanded, the solenoid extends, pushing the bottom of the long part of the inverted L towards the back of the assy. Because the pin (2nd pic) that is in the groove of "B" is near the intersection of the two parts of "L", it moves primarily up<>down. The brass double-grooved thimble "B" is mounted to the tonearm counterweight. When in the at rest position, the solenoid is un-powered, and L w/pin above A, brings pin down into A, pushing down the counterweight and lifting the arm; also, due to the "V" shape of A, it brings the tonearm into a lateral position (parallel to sensor arm) which can be adjusted by turning the screw inside of A; turning it in makes the cartridge move closer to the sensor arm, out=away. (there is a spring the screw goes through that keeps the brass thimble pressing against the head of the screw)
Now, the tacky part which I hunch is wrong with your TT: if you push the solenoid plunger in and the "L" arm fully rearward, the somewhat flat end of the solenoid, and it's hidden attached coil, can be freely rotated. Clearly, the position it should be in is the one that leaves the 2 wires in the "window" (which is above and adjacent the ribbon-wire circuit board where the solenoid wires terminate.) The FIRST photo shows the correct orientation! The 2nd photo shows how it can be indexed 90* out. In that position, it will not let the linkage fully return. There are two tother WRONG positions. Only the one in the first pic is correct! And if you need to re-index, start by locating the wires and gently let them lead you to which direction you must rotate the plunger to which they are attached to get them back to the window without going the wrong direction and getting them wrapped (one full turn) around the plunger.
on 8002 [8000 is different] you can also loosen the single front-most screw on the top of the tonearm, and find about 3* of adjustment there. If the deck tracks records with the arm displaced the same amount during play that it has when parked, then this upper "adjustment" is all that is required and is appropriate!)
And finally, "A" is a stop-screw that the counterweight is stopped by when the arm is raised and the CW comes down. Screwing it in makes the arm park lower/out, higher. I think you need to take the carriage off the tracks to be able to reach it, but you shouldn't need to.
Also, somewhere in these "RAJOD" conversations I recall a question about setting the distance from one or both arms down to the platter. I remember setting to spec on an 8002 and resetting because it seemed wrong. I hunch the spec may relate to 8000 decks, which have quite high protruding ribs the disc rides on; I bet if you subtract the height of those ribs from the spec, you will get a sensible number and what is appropriate on the 8002 with it's virtually flush ribbing. In the same vein, there was a question about `vertical and horizontal parallelism on pg 5-2: "vertical" may be an error or a funny way of interpreting the illustration-from it's perspective it's vertical although it's lateral in the flesh. Like-wise the "horizontal parallelism" if you are sighting across the long sides of the 2 arms and they are "horizontal"! I think maybe it suffered in translation to English.
PS: thanks for stirring my B&O pot, RAJOD. I have 2 8002s and an 8000 to restore and see if I can actually recover some money from on EBay. I was almost finished doing the 8000 when I started building phono-stages and dropped the ball. Now that I got some out, maybe I'll follow through. After that, I need to do 2 Yamaha PX-2s-then maybe I won't feel so "lazy" anymore!
Go Phil! You are not lazy, just taking a needed rest from the project. No hurry, you on your own time not anyone else. Good job on the information.
I think my stop screw needs adjustment because i can raise the arm super high. I'll get to service mode one of these days. I'm lazy too. Hoping that clip will fix most of it.
And yes B&Os can be a pain in the A--. But when they are working I think they are among the best ever made.
That spring-clip retains the "axle" or fulcrum pin the arm hinges on in the vertical. Is it possible the pin is missing or something weird going on there? IE: it should see-saw around that point but not lift up or down.
Not sure. All know is if I grab the tonearm of the good unit it will not move up, only side to side. It hits something so you can't lift it any higher.
On the floppy are I can lift it up around 1 inch from rest (off position) So its not hitting the stop you mentioned.
Phil! Thanks so much for sending me the clip. What are the odds I find someone with a clip and nice enough to send it. Have not put it in yet but soon. I have a parts 8002 on the way so maybe I can tear that one down for some photos of the arm and why mine was so loose.
Just an update. I finally put that spring clip on but it did not seem to tighten up the tone arm much.
I'll probably have to put in service mode to get at it. I'll practice on a parts 8002 I recently acquired.
Phil,
I figured out the Floppy tone arm problem. I took it apart today. It was missing a small piece of foam tape with a copper plate on it. That tape was glued to the underside of the counter weight area and rested on a set screw. That screw is just about impossible to get to for adjustments. Its just to set the height of the tone arm.
I made a replacement part with thick 3m tape.
Not having that spacer there caused the tone arm to do a wheelie on lift off. Now its much tighter because it can't lift past horizontal. The higher it goes the sloppier it gets.
I leveled out the sensor arm using that front screw that a first did not seem to do anything. Its spring loaded and had to push down on it to create a gap large enough to allow my to turn the tiny set screw. Just turning that set screw against the spring does not work well, have to push on the arm by the set screw to do it.
Can that solenoid be lubricated? I just noticed my other 8002 seems to be dampened a little bit more on liftoff.
I just re read this post, very informative.
I want to see first hand some of the components you are describing. That solenoid is hard to see so I think I'm going to pull the rails out.
It looks like those rails just snap out but was not sure if I just pull hard till they pop or is there a trick to getting them out?