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 bought a non-working Beogram 8000 in a pile of pieces that I have just about brought back to life but have a couple questions and am looking for 2 parts if you happen to have them.
1-Does anyone know if the Beogram 8000 shares the sliding tonearm weight indicator window part with another machine? All I have is a loose sliding weight inside the tone arm and am on the hunt for the right part. Also, is the plastic slider and screw the only pieces missing on this part of the tonearm? It sure slides freely inside there. I have it very temporarily held in place with a piece of wire in the shape of a J held on with plastic wrap and tape (not too classy).
2- What capacitor can I use to replace the BIPOLAR 27uf 55v? I made the time consuming and expensive mistake of buying the caps individually rather than buying a kit. Since I couldn’t find a similar replacement component when I was ordering so I thought I would revisit this after completing the recap, I’m a rookie so I just use direct replacements since I don’t know how much I . So, all other electrolytic capacitors replaced and I now have full functioning (other than the worn out tachodisc symptoms) but I would like to complete this recap.
Back story on this Beogram if you like stories to go with projects, I work the night shift in a busy ICU and a few months ago my patient had just died horribly despite our best efforts and as I waited for the room to be cleaned for my next patient I drank a cup of coffee and flipped through eBay. Someone had just posted this table for a super low buy it now (like 3am here) but they knew only that it was their dad’s who had recently died. Feeling the death connection I bought it like 5minutes after it had been posted. I waited to start on this repair until I had finished a really sad 80’s beomaster 5000 system I rescued from the trash. So, after 2 beogram cd50’s, 2 beocord 5000’s, a bg5005 and 3000, and 2 beomaster 5000 all from non-working to working in 2 months I feel as if I have graduated to start this BG8000.
Peter-
Hi,
The tonearm tracking force setting slider is similar to the Beogram 8002 but the tonearms are not the same size so I am pretty sure they aren't interchangeable. You might contact Beoworld member Beolover and ask him what the possibility is of making a 3D printed substitute.Regarding the capacitor in the transformer case, I never change out that capacitor. They have always measured good. If it was bad you might consider this one.
Yes, it is much better to get a list of capacitors you need and get them in one order from a supplier. Piece by piece the shipping costs end up costing as much as another set of capacitors. When you have just one restoration project it is much better to order a kit from Dillen here on the forum.
-sonavor
You are certainly welcome. Once you get this turntable working you might go for some matching components to it like a Beocord 9000 or 8004. They come up for sale cheaply all the time. Then there is the receiver. The Beomaster 6000 Type 225x) and Beomaster 8000 (the beast) go with the Beogram 8000 and 8002 turntables. The receivers and cassette decks have nice displays but they often have burned out segments. There are people on the Beoworld forum who can help you fix them though. All of the components communicate together and there are remote controls that go with them. Pretty nice for very early 1980's. They are some of my favorite Bang & Olufsen components. Of course there are still the speakers. I discovered and love the Beovox MS-150's but the M-70's, M-75's and M-100's are great too. Also check out Beolover's blog. He has some great videos on the Beogram 8000, Beocord 9000 and Beomaster 8000.-sonavor
Three years ago I was of the opinion I would never use cassettes again. But once I ramped up my use of vinyl records and got these old systems restored I changed my mind. Now I am buying blank tapes and recording again. It is difficult to say what a Beomaster 8000 price should be. They aren't real common and extremely heavy so it is a bonus to find one locally where you don't have to worry about shipping. I would like to say $500 for a great condition but non-restored unit is a decent price. I have bought all of mine for a lot less though. However, they all had to be restored before they were working again. If you decide to get it, plan on eventually restoring it completely. Post some pictures if you get it.
Hello, I'm stuck. My tone arm does not set down reliably.
The tone arm positions it self appropriately at the beginning of the record, if I give the tone arm a nudge it will set down and play. With my multimeter I've found the solenoid is getting current at the appropriate time and voltage so I am looking at a mechanical fault. I've read previous posts that there is a teflon sheet that comes loose and can interfere but I have not found anything apparently like that. It appears as if the bar that raises and lowers the control arm is not moving smoothly when the solenoid engages. I referenced this entry http://thearchivedforum2.beoworld.org/forums/t/13012.aspx?PageIndex=3
for how the arm works. Upon removal of assembly I have two thoughts, that the spring that controls the lever is bent and moving the rod crookedly
or that the solenoid when engaged is catching the lever at the wrong angle or something is missing between the solenoid piston and the tone arm lever.
Here is a picture of how the solenoid looks with the lever
and here is how it looks if the lever is just slightly off center. It moves very freely laterally.
\
When assembled, I can take a dental pick to the lowering rod and can recreate the lack of free movement and watch the rod "stick" in a raised position away from the adjusting screw it sets in.
To be clear, you are saying the tonearm moves to the setdown position, then the solenoid engages and the tonearm attempts to lower but doesn't. At that point you can tap down on the tonearm and it will go ahead and lower. Is that the scenario?If it is, then there are a couple of things that come to mind. One is to check for anything mechanical restricting the lowering of the arm. The other is to recheck your tonearm tracking force. It could be that your tracking force is off and you don't have enough weight set to lower the arm. That is the easiest to check first. With the platter removed the Beogram will think it is okay to set down and you will be able to better observe what is going on. Move the tracking force weight up to something like 2 grams and see if it lowers okay. At the beginning of the thread you said you had to rig up a temporary tracking force rig because the original one was lost. Is that still the case?
Sonavor, took your advice, albeit at a better price than expected. The Beast is now functioning at 100% but the Beocord 8004 will be looking forward to taking the Beogram 8000's place on the kitchen table workbench. Next to find some speakers.
Thank you very much, very helpful! Yes, that is the scenario. You pointed me in the right direction, the tracking force appears to be the issue, or most of it. There is a tension spring between the inner adjustable weight and the sliding window that had been dislodged- pushed to the back inner part of the tonearm. Here is a posterior shot of the tonearm where the spring is the copper colored piece near the top of the photo.
I was able to slide the spring into position and now that inner weight does not slide all over the place as it had been but stays were I set it. I positioned the slider window I acquired but the screws I purchased, the 2mm wide x3mm long were too skinny. 0510. My service manual is for all the related beograms and maybe the BG 8000 is different than the 8002/6006.
So, it seems as if the slider window from a BG 8002 and the soft piece of wire now holding the window in place are too light.
It does lower when PLAY is pushed but not every time yet. I ordered a tracking force scale to see how far off I am (all vinyl users should have one anyway, right?) and will continue to search for the right screw to hold the window in place.
It looks like you will have a nice Beosystem 8000 soon. The Beovox speakers I would look for are the MS150, M150, M100, M75 or M70 series. The MS150s would be ideal but the M100s are also really nice. Any of that series would sound good I think.On your Beocord, be sure and order belts and rubber wheel sets from Martin (Dillen). I have used his replacements on several of my Beocord 8004 and 9000 decks. They really make a difference. I see your Beocord also has some display segments out. Beolover has a nice thread about his repair of those displays on a Beocord 9000.
Slight progress this morning with the Beogram. Under magnification I saw there were threads on the dorsal side of the sliding weight in the tonearm (if that description makes sense?) I was able to attach the slider window with a M2 8mm long screw rather than the 3mm long screw leading me to believe that at onetime this tone arm was taken apart and the sliding weight was reinstalled upsidedown so the treads were opposite where the should be so the appropriate screw would not reach rather than the screw diameter being inaccurate as I was thinking last week.
Screw on the right is the proper screw to hold the window in place and the screw on the left is the one long enough to reach the threads. Also, I didn't add locktight (the blue), this screw was removed from a macbook but it is working for now to hold the slider. So, I'm not super excited to disassemble the tonearm to flip the inner weight so I will play with my tracking forces and potentially move the counter weight to account for the difference in weight.
Well, tonearm does not drop with a tracking force less than 1.7grams unless I tap it. Tracking force scale used and counterweight adjusted just fractionally to give me a correlating 2gm tracking force weight with the 2gm mark on the tonearm slider window, same as 1.9,1.8,1.7 after that the arm does not drop on its own. I'm thinking maybe there was a poor repair to the tonearm that is affecting the balance by the person who inserted the sliding weight upsidedown.
Next set of issues: I thought I was getting good sound and speed on previous tests but apparently not. Speed is inconsistent at the beginning of the record and the sound is super wavery throughout. I can watch the cartridge's stylus waving back and forth laterally as the record plays. My guess is that this is related to carriage movement not syncing with platter speed.
And the first minute or two of playing there is a pulsating low drone and the platter is visually pulsating but this resolves and does not come back unless cold.
What I've done, gentle cleaning, replaced tacho disc with metal tacho disc, replaced electrolytic caps with equal value caps. Replaced stretched out carriage belt with appropriate triangle belt. Greased threaded rod with silicone grease, and adjusted photo resistors as described in the service manual. All buttons work as they should including << >>. Starts in the proper place on the record. Stops at the end appropriately and returns home.
I will keep looking at the carriage movement and make sure all is moving as it should and maybe I'll start pulling the box capacitors out and testing them but after that I'm stuck.
Disassembling the BG8000 tonearm is very tricky. You can't easily detach and remove it as the phono cartridge signal wires are continuous from the cartridge mount down to the signal transfer board on the tonearm transport. Those signal wires are the very thin, magnet wire type of wires. They are not color coded and fit through a sleeve to go down the tonearm pivot mounted to the transport. Here are some pictures of some BG8000 turntables I have worked on. This first one is on a broken tonearm and shows what the original weight pieces look like disassembled (Note that the tonearm phono wires were broken off this unit which is why it is disassembled).
Here is the signal transfer board that is the destination for the tiny gauge phono wires.
Here is the sleeve (tube) for the phono wires through the pivot.
Here is the tonearm pivot mount with the tonearm removed from a side view.
Here is the tonearm mounting on the pivot assembly. You can see the small phono wire bundle in the sleeve.
I'm not sure what your speed problems are but would suspect the signal from the sensors that use the tachodisc. You will probably have to look at that output with a scope to see what it is doing.On the stylus movement, that sounds like the tracking sensor adjustment is off. At some point you will need to do the tracking adjustment procedure (5-3 in the service manual). I do that procedure with the P4 connector removed so the platter motor isn't turning (Make sure you only connect/disconnect that P4 connector with the Beogram unplugged!). The rotation of the platter for the tracking sensor is then performed by manually turning the platter.However, you want to get the tonearm balance and tracking force work correctly before that tracking adjustment procedure. It still sounds like something is restricting the tonearm vertical pivot movement if it needs help in dropping. When I restore my Beogram 800x turntables I pull the tonearm transport assembly from the rails and manually check out the mechanical movements...including the tonearm lowering operation. -sonavor
From your pictures, it doesn't look like the tracking force weight is backwards. It is unlikely that someone removed that tonearm as your phono wires look intact. As I mentioned earlier, that is quite a job to remove the Beogram 8000 tonearm. It's not something you would want to do unless you absolutely had to (i.e. wires were broken, cartridge mount broken, etc.). The metal leaf spring isn't centered on the weight in your photo. The way that mounts is the clear, plastic slide knob attaches to the metal weight with the leaf spring there to apply some resistance against the tonearm tube. That is to keep the position of the weight firmly in place but loose enough where a person can slide it to change the tracking force. I had a Beogram 8000 where that screw was too loose and the tracking force would not stay where I wanted it. You can see in the picture of my disassembled tracking force weight how long the original mounting screw is.-sonavor
Under the counterweight is an adjustment screw for the tonearm height at rest.I've seen a couple of cases, where the end of the screw has "dug" itself ever so slightly into the soft material of the counterweight, when itlands on the end of the screw.This eventually causes the counterweight to bind a little to the screw and keep hanging up until the tonearm is touched gently, then itwill drop quite fast (it will practically fall) onto the record (the damping action has already taken place but the tonearm didn't follow).It can have an almost magnetic feel to it.
The solution is either to turn the screw just a little bit, giving it a fresh spot to "dig" or give the end of the screw a touch with a fine file.
Early Beogram 8000s had a teflon (or nylon) sheet placed under the counterweight, it can also bind to the screw the same way.If the sheet is there, remove it and readjust the screw.
Martin
Progress! Sonavor, thank you over and over for the fantastic photos and illustrations you have posted here and with your projects. It makes working with a project that I have never seen before so much more possible than all the guess work from only one non-working example would allow.
The problem was coming from the solenoid. There were a couple of those insulated magnetic type wires coming out from the solenoid housing and catching on the armature from the solenoid and the plastic piece that aligns the tonearm lowering lever.
this picture shows what was happening, the piece of plastic attached to the armature that is pushed by the solenoid was sitting superior to the lowering arm (which is to the bottom of the picture of my tonearm as it is inverted for inspection) and was rubbing with the strands of wire coming from the solenoid (not shown in picture)
here is a picture after the wires were tucked inside the solenoid housing and the piece of plastic attached to the solenoid armature (is indicated by my metal pick coming form the right side of the picture) is in its appropriate place the the right of the armature between the bifurcated points on the lowering arm.
here is the fantastic image from sonavor from another thread I referenced frequently for how things should look
here is a view of the inferior side of the counterweight where I did not find a sheet of teflon but a small marking from the screw Martin (Dillen) mentioned, I gave the screw a slight turn for good measure but this did not seem to be the problem.
Here is a view of the complete tonearm slider window. Such a little things caused so much difficulties.
From the fantastic picture Sonavor posted of the disassembled tonearm I knew that I was wrong in thinking the slider weight was installed incorrectly, the problem was service manual listing the wrong size screw. Indeed the screw I placed was similar to the screw found in Sonavor's picture. I guess it was easy but incorrect for me to blame the unknown person who had disassembled this deck prior to my acquisition of it.
Thankful for Sonavor's words of wisdom, I think it would have been gameover if I would have been brave (stupid) enough to disassemble this tonearm to try chasing down the theory of a previous incorrect.So, now my tonearm is lowering as it should every time and at all weights and correlating the tonearm slider weight with the tracking force scale. The problem with the speeds and wavering sound is gone.
The only issue is when cold the platter still pulsates and the sound I hear from the turntable and correspondingly through my speakers reminds me of the stator from an old tractor before it starts, all pulsating low frequency electro magnetic hum. But this stops either before the tonearm reaches the platter and lowers to the record or after 30 seconds of running (where the sound is of an inconsistent speed) and I'll engage PAUSE until the pulsating audibly and visually stops then the music plays great. So next I will work on my tracking adjustment.
Thank you again for all your help and patience with my learning and trial and error here.
That is great news Peter. Good job on investigating and solving the real problem with the tonearm.Regarding the pulsating of the platter drive, I have seen that a few times when restoring these turntables but by the time everything was adjusted and put back together that problem has always gone away. I believe what is going on is the Beogram control logic is trying to lock in the speed so what you hear is the adjustment procedure. It should come up to speed quicker than that and without all of the readjustment calculations. Maybe Martin can provide some advice on that issue. Congratulations on the tonearm fix.-sonavor
Thank you again Sonavor for your help and encouragement.
I've clocked a little over 30hrs now on the BG 8000 after getting it working and I'm enjoying it greatly. Still having problems with the speed sensing at times. Sonavor mentioned adjusting the the tracking from section 5-3 and this is what I think that is...<<>>>
So I have this adjusted and I'm still having the low frequency hum and pulsating when cold as it tries to lock in the speed. Sometimes just hitting TURN and cleaning my record gives it enough time to figure things out and reach the right speed. If I'm impatient I will grab the center spindle and "twist the nipple"
and then the pulsating immediately goes away. I wonder since it is an issue when the player has been stopped for a little while and powered down that it could be a capacitor issue as if the there was the need to build up a charge to get things spinning at the right speed but since I can physically move things along and the issue with the pulsating stops I'm not sure if it is a mechanical or electrical problem. I've had a couple of the box film 470nf capacitors be problematic in a BM5000 today so I think replacing or testing all the film caps in the BG8000 will be my next best guess since I've replaced the radial and axial electrolytic caps already.
Did you replace all caps, also the one inside the CPU casing and the two at the regulator board?Tachodisc metal and clean?
Problem solved! So it seems after 5hrs of playback and several cold starts. It was unexpectedly the big BiPolar 27uf cap in the transformer box. I had changed the capacitor in the CPU casing and two on the regulator board, this is the board near the tonearm carriage with 2 caps and 2 transistors right? (initially I had only replaced the 47uf and ignored the 0.22uf film cap, looking at others repairs and from the service manual the 0.22 cap was suppose to be a 1uf so I switched it and nothing changed so I put the 0.22uf back in place since it tested fine). Tachodisc is new, metal, clean and installed exactlky according to Martin's instructions). I pulled and tested every film cap on the board and everyone was within specs. I had forgotten about the 27uf by the transformer and had previously ordered several close replacements since an exact was not to be found. The Wicon tested at 34uf rather than 27uf so instead of trying the 33uf I was planning on using I tried a 22uf (+- 20% close enough right?) and sure enough it solved the problem, I don't wonder if the 33uf would have worked and the old capacitor's inability to stay stable due to age was the problem rather than the capacitance it was settling on. Please feel free to correct my thinking and diagnostic process, half the reason I love this project is from the learning opportunity.
All that is left is to attach the aluminum surrounding the platter with double sided tape and I think this beogram is back in action. 2months of on and off work and waiting for parts, well worth the effort I think. Thank you all for all your help, I truly appreciate it.