[Nebojsa Jankovic]

Can anyone confirm if Beocenter 7002 and 7007 have the identical LED display, please? I can get a former with functional  display very cheap and use it as a donor for my BC 7007!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Your photo shows a female input of your BM, which should mate with a male DIN5/7 plug, which should be wired as in the attached photo. Attached photo shows the back of the DIN plug (solder view). If all of this is correct, it does seem that the DIN plug wiring pinout should be reversed as in a mirror image, to match your BM input plug. Also, check on your DIN plug if you have wired also the plug housing…

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Hello again, as I feel it is essential for the success and value of our forum, to provide an update on the successfull resolution of my problem on the BC7007! I had reported two issues, primary of the system power-down after 10-30sec and secondary of the issue on the left channel on the Speakers1 output. Both causes had to do with failure mechanism of component wear, logical and expected on a 50-year old system!

Power-down was diagnosed to go back to the surface corrosion on the two potentiometres (adjustable resistors in either left and right amplifier circuit), that provide bias required to be precisely at 1.1V on the emitter of transistor Tr210, see attached photo of this part of the circuit for the left amp (R224 and TR210, circled red and green respectively). After cleaning of corrosion with contact spray onboth potentiometres and fine adjustment back to 1.1V, power-down issue went away permanently!

Speaker output issue was traced miracleously to a short inside the Line-in plug on the rear connections terminal (white/light grey cap), so this was permanently fixed by going a step inward, bypassing the plug jumpers by creating permanent connection on the back board of this circuit located in the back of the in-out terminal. Additionaly, as during this exercise, issue of channel output began moving back-forth between Speakers 1 and 2, this was traced to intermittent function of the speaker 1/2 buttons on the main system control panel, so their respective back contacts had to be also cleaned by contact spray!

I hope this may help our team members, as they experience similar symptoms!

Kind regards!

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

A self-correction is due, as I now see that I mistyped, it should have said “lots of work, easily 100 hours”. All have gone into diagnosing, fixing, modelling, reading circuits, adjusting electrically, physically, testing, retesting, trials and errors…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Hello Madskp, I cannot agree more with you! I just posted those to illustrate my point, made and summarized very explicitly earlier! I have also done multiple cross-checks for the online information and have concluded that I can only trust what I see and what I probe. On the image posted by Layesera, I can see clearly white (to pin 3) and red (to pin 5) wires, left and right high signal, yellow for data (to pin 6), but then 3 other wires all seem black, so one of them should go to pin 2 (shield), one to plug housing… And this image is a view from the solder side of the DIN plug, inside of the plug.

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Incredible piece, complicated design, but extremely sensitive! Typically, during its 50 year life, people have worked on it, so have likely changed things, fixed some, created and left hidden problems behind… Components had not been made to last this long, so are now walking wounded issues. It requires extremely precise mechanical/physical alignment between stationary and moving sub-systems, coupled with analog components that deteriorate, so any bit more complex fix and service may work out, but can also screw up its incredible balance by design! All of the boards in my system have by now been resoldered on every point, 60% of components that have naturally aged have been replaced (once a board is out, this is the most prudent thing to do…), every mechanically moving part dissassembled, serviced, cleaned, greased, reassembled, realigned, all tested, functionally and electrically etc. Incidentally, if one is lucky, they can be very happy, as 5 years earlier I had bought a fully working/serviced 4002, and it still works perfectly, without anything touched in it! Hope not to have cursed it for my son, who has taken it over from me!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

I bought a 4004 for €550, with an issue on the tonearm, would not go down on the LP… Since then, I have made it perfect, but has cost me 4x the additional investment, with lots of work, easily 300 hours) and learning, with great help from Rudy, himself and his video blog, plus lots of work from a local HW specialist… It has been a long and difficult process, but fully worth the experience and result, as this is to be expected from a 50 year-old vintage piece of amazing design and engineering! Remember, B&O offer the new limited number release of Beogram 4000C to european customers at €20.000. They are all probably gone… They also now offer refurbishment service for the 4000/02/04 and that won’t cost less than €5000… So, go for it, if you want to keep it for the next 20 years!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

most of the time pin numbers are as in the attached photo, looking at the inside of the DIN plug, the solder side. Also, see some online information specifically for the BG7000 system, BUT in this case, I can’t be sure if the numbers are from the solder side or the face-side of the plug…

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

I asked you earlier what exactly is wrong with your cable, because if the cable itself is not physically damaged anywhere, it is highly likely that your problem is inside the DIN plug, where a wire solder connection has come loose! Therefore, your best bet is to carefully open your DIN plug and check it out visually for any opens on its pins! As Guy also wrote in the meantime, even if you source an open-ended DIN7 cable, you will still need to identify its pin-out between DIN pins and open ends of its core wires, either by using multimeter or opening the DIN plug…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

here is a typical image of a DIN7 plug, the solder-side of it

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Hello, yes, pinout is vague, because it requires common sense, rather than blind following! Here is a summary:

– There is no DIN fly lead cable with identically colored wires, as in your BG7000

– Noone can give you this for your system! I tried to look at the RIAA diagram in the BG7000 service manual, but could not conclusively identify its output channels!

– you need to identify, by YOURSELF,  the pin-to-pin connections between the output of your RIAA board (as in your photo, see attached) and the back of your DIN7 plug, that would be what is called “solder side” of the DIN7 plug

– therefore, you need to open your DIN7 plug and see the inside of it, so you know for certain how its pins are connected back to the output of your RIAA

– online diagrams refer to DIN plug pin numbers 1-7, but it is not always clear looking from which side of the plug, the solder side or the outside of the plug, so tobe absolutely sure, you need to do this yourself!

– Once you have identified RIAA-to-DIN pin-to-pin connection, you can take any cable with 7 wires and manufacture your new cable!

kind regards

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

What Guy suggests is a pre-wired DIN7, so you need to make sure you take the correct pins and solder their wires to the right terminals of the RIAA, badically following the exact pin-out of your DIN7 cable! Alternatively, as the original B&O cable cannot be sourced anymore, you just need to get a generic cable with 6 wires, plus shield and a new DIN7 plug and make your own cable by copying the pin-out from your existing cable. (Not to mention that you actually may not need more than 3 wires, plus shield, if you use your Beogram as a stand-alone turntable.) If you are handy with a multimeter, you can also check what is wrong with your cable and fix it!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Hello Martin, if I may ask, in order to reach the solder side on the main board of the BC7007, do all of the components, that are now on top of it, need to come out before the board itself would be removed or is there a way to get to its solder side by removing the bottom pannel of the beocenter?

Thanks in advance for any help!

Kind regards, Nebojsa

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Thanks Martin! Will get on with it, as I also accidentally noticed that one of the “Speaker 1” outputs does not work, as I have always used “Speaker 2” channels…

Nebojsa

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

An update from myself. As I wanted to test another set of speakers on my Beocenter 7007, I used the radio as a sound signal and found out that the system shuts itself down after about 20-25 seconds. Turned back to the turntable and it played the LP (Steely Dan Live) properly for about 25 secs and again system shut itself down! So, this leads me to believe that this symptom has to do with the power supply and/or supply circuit itself. Any ideas, please?

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Potentially a great deal, if for anything, just the MMC6000 cartridge, if it works, is alone worth more! If it works… On the turntable, you could get VERY lucky, but that is unlikely! So, step by step, $ by $, you could easily end up with another US$2000 in it, so you must decide if you want this wonderfull engineering masterpiece to become yours to keep and charish for another 40 years! You will know what you did to it, you will enjoy making it as well! Alternatively, you could just find a working one for less, say $1000-1500 and enjoy it equally… In a former scenario, just sticking to it and reading and learning from Beolover vlog and write-ups, you can go a long way and really enjoy the process of converting something that does not work into a beautifull working vintage deck!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Hello Peter, as we see quite various suggestions, here is another one. At DK Sound Parts (dksoundparts.com), you can order exact metal replacement pulley (part#MP-011) and matching belt, with triangular profile (part#BS-024).  See attached images!

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

[Nebojsa Jankovic]

Having persevered in asking for details over 3 days with the FJS team, this is what I learnt, so want to share with the forum. Needless to say, with big thanks to FJS and for their courtesy!

On the Diamond tips:

The main difference between a Nude Line Contact needle and a Nude Shibata needle is the shape and geometry of the needle tip, which affects sound reproduction and tracking ability.

1. Nude Line Contact: This needle has an elongated, flat tip that offers a larger contact surface with the record. This allows it to capture more details and nuances of the music, especially in the higher frequencies. The shape allows for more precise tracking of the grooves, resulting in better sound quality.

2. Nude Shibata: This needle has a special, rounded shape that also offers a large contact surface, but with a different geometry. The Shibata needle is known for its ability to reproduce even fine details in music and is particularly well suited to reproducing complex sound structures. It can cover a wider frequency bandwidth and offers very precise tracking.

In summary, both styluses offer high sound quality, but with different geometric properties that affect the way they sample and reproduce music. The choice between them often comes down to personal preference and the specific application.

On the Cantilever/carrier:

The main difference between a sapphire cantilever and an aluminum cantilever lies in the materials and their properties, which affect sound quality and tracking ability. Here are the main differences:

1. Material:
– Sapphire cantilever: Sapphire is a very hard and lightweight material that has a high degree of rigidity. These properties allow for precise tracking of the grooves in the record and contribute to clear and detailed sound reproduction.
– Aluminum cantilever: Aluminum is also lightweight, but not as hard as sapphire. It offers good rigidity, but can lag slightly behind sapphire in terms of sound reproduction and tracking ability.

2. Sound quality:
– Sapphire cantilever: Due to its hardness and rigidity, a sapphire cantilever can often offer better detail reproduction and a clearer sound image. It is particularly well suited to reproducing fine nuances in music.
– Aluminum cantilevers: While aluminum cantilevers can also offer good sound quality, they may not be as precise in tracking as sapphire cantilevers, especially with complex or dynamic pieces of music.

3. Durability:
– Sapphire cantilevers: Sapphire is highly scratch resistant and has a high durability, making it a long-lasting choice.
– Aluminum cantilevers: Aluminum can be more prone to warping or damage, especially if not handled carefully. In summary, sapphire cantilevers typically offer higher sound quality and durability, while aluminum cantilevers can be a more affordable option that still offers good performance. The choice between the two often comes down to personal preference and budget.

Generally on diamond:

Different diamonds enable different reproduction in the range of frequencies to be achieved. The higher the frequency response to be achieved, the higher the reproduction quality in the area of ​​the spatial sound of the treble, bass and mid-range. So, the higher the quality of the diamond needle and the cantilever, the higher the reproduction quality.

The tracking force that we specify per head is the recommended tracking force with which we achieved the best results.

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04

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