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
Hi,
As a preface, I have attempted to search for similar issues here and elsewhere, and didn't find anything. I hate posting questions / help requests when a simple google will suffice!
I recently bought a Beogram 4000 in an auction (Sweden) and took it home to find out that I'm not getting any audio from it. I believe I have the right set up, and am trying to troubleshoot what could be going wrong otherwise. The seller could not show that audio worked as he did not have an amp, but I did see everything else looking like it worked before I purchased it.
My Setup
When I plug everything together and turn on the record player, all I hear is a loud buzzing sound through the speakers. I've tried MC mode on the pre-amp and tested even directly connecting the record player to the amp, but still no sound - just buzzing of different amounts. I use the grounding wire from the record player with the Pre-Amp, which does help a bit, but doesn't solve the problem.
So I took apart the record player using Beolover's guides. I noticed the tone arm linkage had seized, and fixed that. I also gave the interior a good cleaning and ran the player with the covers off to make sure nothing else looks strange - all the mechanics seem to work.
So now I'm not sure where to go. I hope I'm being an idiot and forgot a crucial (and simple) piece to the puzzle, and hope there aren't more serious issues wrong with the player.
Any ideas are welcome!
The only part of the turntable that affects the audio signal is the path from the cartridge to the plug that connects to your preamp. So start at one end and diagnose to the other. A very common source of this kind of problem is the phono cartridge itself. Also check the phono plug that connects to the preamp. Do some continuity checks including the shields. There could also be problem with the muting relay. That relay is the only component (besides connectors) between the audio signal from the phono cartridge to the preamp plugs. A buzzing sound can also occur if the phono cable isn't grounded properly to the preamp. Non-B&O preamps typically need their chassis ground connected to the Beogram chassis.
It would help if you showed a picture of your connection to the preamp.
-sonavor
Thanks for the quick response and idea for next steps! I actually did tweak the muting relay while I had the top off just to make sure that wasn't causing any issues. I used Beolover's videos.
When I worked on the tone arm I took the stylus cartridge off. This one came with the purchase, so it could be faulty. When I went to put it back on I noticed that what looked like the actual contact point (which should be attached to the downward facing piece of plastic protruding from the arm) was loose. I made sure it was in the right place when reconnecting the stylus, but this could also be a possible issue.
I'll post some photos tomorrow of how everything looks.
It is really common for the Beogram 4000 turntables to have broken cartridge connectors. It sounds like yours has started the connector failure process and is likely broken inside. That contact being loose is a bad sign. However, as you can see on the Beolover site there is a replacement available to repair that problem. It requires some careful work and good solder skills but the results are excellent. I have two Beogram 4000 units that both have had the cartridge connector replaced.
Alright, here is an album of photos of the entire record player.
https://imgur.com/a/2DmjyK1
I've "traced" the audio signal from stylus to the DIN connector and don't see any obvious issues (minus the one stated above regarding the cartridge connector, which I have provided closeups of). The DIN Connector looks quite old, but doesn't look damaged. I did notice that the thick yellow and gray wires that comes out of the mute switch were being rubbed by the turntable, and had left a black mark on them. It doesn't seem like it exposed the inner casing, so I don't think there is any issue there. I did make sure that they were resting a bit lower, so this doesn't happen any longer (you could hear the friction when the turntable was spinning).
I have also included a close up of the muting relay. I made a few adjustments to it based on Beolover's videos, hoping that could have been an issue, but it didn't change anything.
Photo of the DIN connector to the pre-amp (I know, the pre-amp isn't plugged in!) This is how I have it connected, and then with phono cables to my amp. Let me know if you want to see shots of that too. The amp works fine as I use it with music streaming, and with my newer record player.
There are also some smaller issues with the Beogram's functionality, like the carriage speed modulation not always working when moving right (moves slow most of the time, sometimes jumping to faster speed if the perfect amount of pressure was applied), and the dead bulb behind the tracking display on the control panel. Would it be worth packing the entire thing up to send for a big repair by Beolover (assuming he does that kind of thing?)
You photos show that the thin strip of cable for the cartridge mount connection is loose and not fixed to the black plastic shell. I would suspect that as being the most likely source of the problem.
You might try removing the cartridge and platter belt (or removing the platter) and operating the Beogram where it thinks it is playing a record. When the muting relay clicks off check if you hear any buzzing or noise through the phono input of the amplifier. It should be silent.
I can recommend contacting Beolover for a Beogram 4000 restoration/repair. I worked with him on mine and I know he has done quite a few.
Thanks, will try this out over the weekend and report back!
So I put everything back together again and tested as you instructed - buzzing persists even when mute switch is triggered.
I did notice, however, that the buzzing starts even before I power on the Beogram (the amp and preamp are powered on). This leads me to believe that there might be an issue with something in between the Beogram and the amp (amp should work since I use it with other record player). Could it be the DIN adapter or the preamp?
I noticed that the amount of buzzing changes based on the position of the preamp, and how far from the power source and amp it is.
Any ideas?
This is the DIN adapter that I am using: link.