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 remember the first time I saw those bits floating loose inside the chassis. Took me awhile to figure out how they attach. And of course in the SM, there is NO drawing showing them!
Today I cleaned off all the old residue from the double-sided tape that secures the top aluminum plate, the lower tonearm bay cover and the tonearm bay lid. This picture show the lower tonearm bay cover.
This picture of re-attaching the deck cover shows the new double-sided tape pieces in place (on the underside of the deck). The bottom picture is the deck back in place.
Starting to wrap this project up now. The top part of this picture shows the Beogram with the cover piece in place over the main hinge. The bottom part of the picture shows checking the tonearm force. The slide scale on the tonearm for tracking force was slightly off but not by a enough (not an entire mark) to take it apart and try to adjust it. To set the force to 1 gm the tonearm slider is a couple of hair widths past (forward) the 1 mark.
Back in service.I installed a nice, working MMC2 cartridge and I am now able to use the Beogram 8002 for the purpose it was intended.
Now I can break out the champagne.
-sonavor
sonavor: Back in service.I installed a nice, working MMC2 cartridge and I am now able to use the Beogram 8002 for the purpose it was intended. Now I can break out the champagne. -sonavor
Wow John. congrats, that was one of the most interesting threads I have seen on this forum, a real pleasure to follow and learn from, and a finish with attention to the details, now enjoy.
Collecting Vintage B&O is not a hobby, its a lifestyle.
At 5:30 pm my time I will lift a glass toward the west. Congrats.
What's the rest of the system it will be in?
PS Received my P30s yesterday and all drivers work. Happy days!
Thanks! I appreciate it. I also appreciate all of the help you guys provided.
My plan is this Beogram 8002 will be part of the system below. The Beogram 8002 in this picture is my original one however as I am using the repaired one in its place (temporarily). The next step for me is to finish Frede's Classic Audio Tester, then refurbish the Beovox MS150.2 speakers that go on the stands shown in this picture. After that I plan to start on the Beomaster 8000 shown below. Last, will be to fix up the Beocord 9000 shown in the picture. The Beocord is in good shape and does play. The last time I checked it out the only problem it had was with the fast forward not working.
Beautiful with the furniture, my offer to make stands and maybe frets stays
Thanks Søren. I'll try and take some pictures with measurements and email them to you soon.
The champagne is good (and cheap here) John !
Well done !
Your photo oddly looks like home!
Cheers!
What's behind the BC9000?
Jacques
The B&O cabinet has a compartment behind the Beocord 9000 with a metal cover to match up (visually) with the BM8000 heatsinks. It looks like the compartment is for routing all the connection wiring so they don't hang down in the back. I put a power strip inside the compartment so I only run one wire to the wall outlet.
chartz: What's behind the BC9000?
Well spotted!
Of the decks BC9000 or BC800x, which would be everyone's choice? Always wanted one (along with a Nakamichi BX-300).
Anyway, finally got home to raise a glass to John. A bourbon rocks is looking west. Cheers!
Wow, great thread! I don't follow most of it but I'm sure it will help plenty of people out!
I've recently picked up an 8002 as a bit of a project. Similar issue with it to this thread too, she starts automatically when plugged in. Changing from 33 to 45 works fine, but no other controls do, and the tone arm is parked. I'm going to start with the push-buttons as the << and >> "feel" different when pressed, they almost sag instead of click, so I'm hoping its just stuck on >>, but we shall see!
I'll start a new thread when I get chance to open her up.
The buttons are suspended on copper leaf springs, which need to be bent upwards again to restore the firmness.
You should resolder the black wires while you've got the keyboard open - the soldering has a habit of degenerating to a "dry joint".
And if you like, you can convert the lamp to an LED to minimize the necessity of future replacement. Circuit modifications are required if you do that.
Menahem
Hi. I have recently aquired the same turntable & have had my local technician perform all the changes specified in this posting but the table is still erratic; very intermitant. He is thinking the main processor may be at fault. My question is if that is indeed the issue is it available & from where & at what cost? I would really like to get this Beogram up & running as I had one in the 80's & loved it. Any help/advice would be appreciated.
Erratic behavior is pointing a large finger at dry joints.
Has he resoldered every single joint on the PCB's? No shirking and no making things up now!
And use good old environmentally-unfriendly Leaded Solder, if you want the joints to last.
Sometimes, jumping to expensive and unobtainable solutions like a "new processor" is a waste of time, when the real answer is staring you in the face, but it just needs an honest approach and diligence to do this time-consuming task, instead of wishing for magical solutions.
The problem is that even if you could still get a new, replacement processor IC, it would have to be programmed. If the processor is bad your best bet would be to find a "parts unit BG8002". However, while it is possible that the processor could have a problem, I think it is more likely something surrounding the processor is causing the intermittent behavior. I think the processor would either work or not work. Other Beoworld members that helped me during my rebuild suggested looking for solder connection problems. That was good advice. There are some bad solder connections you can't see so re-flowing the solder joints is probably a good idea. I ended up re-soldering most of the components. The board is small and the solder points are too so you just have to go slow and be careful. Definitely worth fixing though.
This weekend I needed to adjust the set down point of the tonearm on the record for my oldest Beogram 8002
The service manual has a diagram of this but I thought it would be good to post some pictures. The first picture shows this adjustment can be made by opening the black, rectangular plate below the tonearm.
This picture shows the adjustment. Note, make the adjustment with the tonearm out of the way. Turn the Beogram on, move the tonearm out of the way, then unplug the Beogram so the tonearm remains where you want it. The picture shows a screw driver turning the mounting screw. This will rotate the switch arm left or right. To move the tonearm set down point further into the record, you want to move the switch arm to the left. Only use the screw in the picture to move the switch arm though.After you move the set down position screw (and observe the switch level move), test the position by plugging the Beogram into an outlet and pressing play.
I have started in on another Beogram 8002. So far I have installed a new capacitor kit and tonearm belt from Martin. The Beogram only partially works though. I am having trouble determining if the source is solely electrical or also mechanical.
All of the control panel buttons appear to work.I press Turn and the platter turns. Buttons for speeds (45 & 33) change speed. I press Stop and the platter stops.So far, so good except that when I continue testing and press Play, the turntable starts to play but the tonearm stops moving forward after about 20mm of travel. I can increase that by manually holding the SO switch but that isn't the real problem. The Stop button will not function after I press Play. The Forward and Reverse buttons will operate but not Stop. Stop only works when the tonearm is at the initial rest position and I press Turn.
I would suspect all of this is some sort of electrical problem with the Beogram control logic and maybe it is. But another thing I notice on this unit is during Forward and Reverse. Forward is always smooth which Reverse results it some jitter (vibration) in the arms. So is that a mechanical problem with the carriage?As for auto-stop...when the carriage travels the maximum distance, that functionality only occurs when I hold the Forward button until the arm reaches the end (record center). However, when the carriage reverses direction to stop, the arm assembly only moves about 10mm to 20mm then stops. If I unplug power and then plug it back it, the arm will move another 10mm to 20mm then stops.
I am hoping this is all related to something electrical as that should be able to be found and fixed. If there is a problem with the mechanics of the arm carriage, that will probably be more difficult. This Beogram appears to be well taken care of and has no visible damage. So it seems strange that the carriage exhibits vibration in its reverse direction.
I have one Beogram 8002 spare that I am also planning to repair so I can try swapping some parts to help isolate the problems. Has anyone on the forum seen this type of behavior with the BG8002?
Did you reflow the CPU socket solders and where the ribbon cable meets the main board ?And of course the edge connectors.
Martin
Here is a picture I took when I opened the BG8002 CPU case. It shows the processor chip stuck to the lid.
I also went back and checked and realized I haven't reflowed the solder connections on CPU socket so I will do that today.
It's quite common to see the CPU stick to the metal cover rather than its socket.It's because the metal lid is used as a cooling fin and the cooling paste hardens.
Check also where the ribbon cable is soldered to the main board and all the edge connectors on the main board.
TIP: To remove stubborn and hardened cooling paste, give it a shot of contact cleaning agent (the type without lubricants!).It will dissolve the cooling paste in seconds and you can just wipe it off with tissue paper or a soft cloth.I use the "Kontakt 60" from Contact Chemie. It evaporates fairly fast and almost completely.
I made some progress but didn't quite get the result I was hoping for.
Reflowing the CPU board changed the conditions but not in a solved solution state. There is still something wrong with that board (or the cpu). As a test, I took the CPU board from another Beogram 8002 unit I had waiting for repair. I recapped the lone, 10uF electrolytic on that CPU board, then tried it with this Beogram I am trying to complete. That worked. The Beogram Play and Stop functions work as they should.
However, there is still the vibration jitter on the tonearm assembly when it is returning back to start position. Everything is well lubricated but the return travel is behaving like something is out of alignment. Forward travel is fine though so I am not sure what to adjust.
On the CPU board that is still bad - I guess I need to try a different CPU chip and see if that is problem or if the problem is with a board connection. Are the CPU modules on the BG8002, BG8000 and BG6006 compatible? The service manual lists all three units but only calls out one part number for 02 IC1 uC chip (8340454 124 R 1093). I have a couple of BG8000 turntables waiting to be fixed. I will check their 02 IC1 chips and see what their part numbers are.
Another update...
I dug out the processor board from one of my Beogram 8000 turntables I had already used for parts. The CPU part number (B08340454) matched the number on the working processor board so I pulled the IC and installed it in the original board that is not working. The result was a return to the functionality I had last night for that board. Some functions work but the Play and Stop functions are not working correctly. So there is still some problem with that processor board. I will need to try and rework it and try again.
On the tonearm vibration problem (during reverse), I can gently apply a little force on the arm carriage while it is moving and observer the vibration stops. The force I used was to move the carriage towards the front of the Beogram. So I need to make an alignment adjustment to the carriage assembly. Below is a picture of the two Beogram 8002 processor boards. The one on the left is the non-working one with the IC1 chip from the BG8000. The one on the right is a recapped processor board from another Beogram 8002 that does work.
In comparing the BG8002 main boards between the one I am currently trying to finish and the one on deck, I notice that the current Beogram unit has a modification that adds, what appears to be a resistor, across the connectors for the tonearm motor. Here is a picture of the schematic where that component is added.
Here is a picture of the actual modified board
Here is the board without the modification
Regarding the vibration in the BG8002 tonearm carriage - I checked another BG8002 and its carriage assembly is a lot tighter, very little play. The carriage assembly of the Beogram I am working on is rather loose.
I wish you luck there - I've never seen this problem.
On all these types of PCB's, I always remove the CPU, spray Contact Cleaner into the sockets, then reseat the CPU - there may be corrosion in the sockets.
Also check all the soldered joints of those grey ribbon cables - that one or more cable conductors hasn't broken due to fatigue.
I also see a couple of suspect joints around C6 - did you resolder all the joints on the underside?
The Beogram 6006 and 8000 CPUs are interchangable.The 8002 is not.Apparent differences are that it supports the two little arrows on the sensor arm and it hasa different coding to support multiple play repeats but there are other things too.Don't expect it to work and - to be on the safe side - don't do it. Those CPUs are quite sensitive and not too plentyful.
And don't think too much about the added resistor, it's quite common and found on many boards.There are countless modifications and variations in these decks and some even have two, occasionally three, smaller piggybackboards added.
Reflow all the main board edge connectors, even if they look fine!
The vibrations are most likely caused by a worn nylon bushing under the carriage.If that is the case, I suggest you lubricate the threaded shaft with a little silicone greaserather than oil.
Finally a break through.
Yes Menahem, I also usually drop some contact cleaner in the sockets. With this board I carefully went over it again and even resoldered the 21 pin IC socket. Looking at everything through magnifiers it all looked good. I finally did something I should have tried earlier, I swapped out the control panel. Now the functions look like they are working again. I will need to put everything back to test for sure but it is looking successful right now.
What about the tonearm carriage though? I don't see anything in the manual about adjusting the actual carriage, just adjustments for the arms. Does that mean I have to disassemble the whole tonearm carriage from the guide shafts (rails) and drive spindle?
I replied before seeing Martin's reply about the silicon grease. I'll try that next.
Some more positive news.
The grease seems to help. I also re-installed the original IC1 CPU chip out of this Beogram and it is working. I'm glad it is okay. Tomorrow I should be able to put this turntable back together for some real tests. I am also going to take apart and clean the original control panel and see if I can get that working again.
This Beogram 8002 is the last piece of a Beosystem I have been restoring. The system consisted of a Beomaster 6000 receiver, a Beocord 8004 HX-Pro cassette deck, a pair of Beovox MC120.2 speakers and the Beogram 8002 turntable (with an MMC1 cartridge). I used repair kits from Martin on all the pieces except the woofer surrounds on the speakers. I used surrounds from Good Hi-Fi for those as I have used those same surrounds successfully before. The repair kits from Martin included replacement capacitors and belts (where needed). Since restoring the Beomaster and the MC120.2 speakers, I have been listening to them for several days. The MC120.2 speakers sound really good. The Beomaster sounds great too. I had been testing it with a pair of Beovox S55 speakers. The MMC1 cartridge had a bad suspension so I sent it in to Soundsmith for repair. They will verify the stylus and cantilever is good before they do anything. I really hope it is okay. If it is, the repair will be the first time I have used Soundsmith for a repair. So far I have used Axel Schürholz and Benny Amina successfully for MMC2 suspension repairs. If the MMC1 repair is successful I will post pictures of all three repaired cartridges.
What is a good tape to use as a replacement to the original Beogram 8000/8002 control panel. That is the tape that covers the small pushbutton pads. I have one control panel off a Beogram 8000 that really would do better with new tape.
Thanks,sonavor
I ended up salvaging the existing tape on the control panel. I would still like to know of a suggested replacement for that tape though.
Meanwhile, after reflowing the solder connections on the processor board joints where the control panel connections connect, I have the Beogram operating pretty good.
Today I restored the aluminum panels that always come loose ... due to aging in the double-sided tape that fixes the panels to the chassis.First the main deck.
Then the tonearm bay lid