Algroen6500 wrote:

Hi there fellow B&O enthusiasts!

Recently I've been having troubles with my Beomaster 6500 which worked perfectly fine, however, not anymore. The reason why I started working on it was that I wanted to connect an older Beogram (1600) which wasn't RIAA amplified and I magically found the original spare part for sale nearby (part: 8001245 which was new in box)!

So during the weekend I opened up my Beomaster and carefully removed the logic board which needed the installation and installed the part into the logic board just like the steps that were mentioned in the manual (can provide this if needed). The manual said I had to cut two jumpers and one pin in the phono powerlink socket which I also did according to plan.

After the installation of my RIAA pre-amp I decided to spin my vinyls again and play it on my restored Beovox cx100 loudspeakers, but I was struck with disappointment. I couldn't hear any sounds coming out, not even from the radio or so. The only moments I hear sound coming out is when I turn up the volume to the max and it is very inaudible. This also counts for using the headphone socket. Later on I decided to try a pair of active Beolab loudspeakers which gave sound, but the next day it was gone? The first thing I found online was that maybe the relay switch had oxidized over time and made poor contacts, so decided to spray it with contact spray and give it a shot, unfortunately still no sound. Second attempt was re-soldering a loose connector on the logic board that gave some static sounds when I was troubleshooting, unfortunately still not the answer to my problem.

Long story short: my pretty and fully functional Beomaster 6500 does not give any audio signals to my Din/Powerlink/headphone sockets anymore after I installed the RIAA kit.

I hope any of you might know where to look for and can help me out!

Thanks in advance, 

Alain 🙂

Did you remember to put the white plastic connector back into the LINE socket ? If this is not there, no sound can be heard. If this is plugged in, the only thing that can be, is that you either installed the module wrong/cut wrong wires or something, or you have broken something else. The speaker relay is only for passive speakers, so using the powerlink sockets will eliminate problems with the speaker relay.

/Weebyx

Weebyx wrote:

Did you remember to put the white plastic connector back into the LINE socket ? If this is not there, no sound can be heard. If this is plugged in, the only thing that can be, is that you either installed the module wrong/cut wrong wires or something, or you have broken something else. The speaker relay is only for passive speakers, so using the powerlink sockets will eliminate problems with the speaker relay.

/Weebyx

Hi Weebyx,

Thanks for your response, I tried plugging back the plastic connector and I had sound on the active ports and the mcl ports! Probably a rookie mistake 😕... However, the volume won't go to the max and turns off the device as soon as it reaches volume levels in the 40s while it goes all the way to 78. So that's still open for further investigation this weekend.

In an other topic I red about the headphone jack which might influence the relay and muting functions, so I will definitely try to look into that as well and check the logic board once again for poor/bad solderings. 

Thanks once again and have a nice Friday!

Algroen6500 wrote:

Weebyx wrote:

Did you remember to put the white plastic connector back into the LINE socket ? If this is not there, no sound can be heard. If this is plugged in, the only thing that can be, is that you either installed the module wrong/cut wrong wires or something, or you have broken something else. The speaker relay is only for passive speakers, so using the powerlink sockets will eliminate problems with the speaker relay.

/Weebyx

Hi Weebyx,

Thanks for your response, I tried plugging back the plastic connector and I had sound on the active ports and the mcl ports! Probably a rookie mistake 😕... However, the volume won't go to the max and turns off the device as soon as it reaches volume levels in the 40s while it goes all the way to 78. So that's still open for further investigation this weekend.

In an other topic I red about the headphone jack which might influence the relay and muting functions, so I will definitely try to look into that as well and check the logic board once again for poor/bad solderings. 

Thanks once again and have a nice Friday!

Yes, I have myself forgotten to plug back the white connector after servicing these units, then to find out that no sound is there, and panicking since I then must have killed something :)

The Line connector is used to be able to send the line signal to an external equalizer, before sending back to the beomaster for amplification. If this plug is not there, the line signal will never get back into the BM and no sound is produced.

Regarding the volume issue, was this also there before the RIAA upgrade ? It sounds like the protection circuit is kicking in, but this requires more than just "change this" advice.

/Weebyx

Weebyx wrote:

 

Yes, I have myself forgotten to plug back the white connector after servicing these units, then to find out that no sound is there, and panicking since I then must have killed something :)

The Line connector is used to be able to send the line signal to an external equalizer, before sending back to the beomaster for amplification. If this plug is not there, the line signal will never get back into the BM and no sound is produced.

Regarding the volume issue, was this also there before the RIAA upgrade ? It sounds like the protection circuit is kicking in, but this requires more than just "change this" advice.

/Weebyx

 

Well I think it is already a sign that it somewhat started working again... So at least it receives the audio back and is able to process the audio like it is supposed to. However, I didn't have any of these protection circuit troubles before I installed the upgrade.

What I did in the meantime (before I found out that I had to plug the plastic back in) was burn a little hole in the plastic casing of the relay switch to check if that wasn't oxidized and spray it with a little bit of contact spray, with no effect obviously. 

I don't have any clue regarding the protection circuit kicking in apart from that I switched the voltages from 220v to 240v (local voltage is 230v) to reduce my power supply humming noise and ensure the endurance of the power supply. I will definitely check again tonight or tomorrow what the exact behavior of the protection circuit is like since my previous tests were a little rapidly.

Alain