If you suspect the noise is caused by bad solder joint or loose connection, try slamming the case, if problem goes away instantly, there IS somewhere has to be resoldered. Or you can open the case and press the different positions of boards gently to locate the problem.

Humming voice usually comes from bad grounding.

Hello Vassilis, welcome to the forum

I have  had the exact same issue as you describe on my Beomaster4500, but on one channel only. it has been at B&O service center 4(!) times for the issue. they have changed different parts every time and the issue disepears. whats really anoying is that the issue apears again after some time, so I have had it now occationaly for years, it seams that it is worse in winter time, and fore me it has disepeared for half a year without doing anything.

I have tested to mute the BM over nigth instead of puting it to stand by, and then the hum will not apear when I unmute, but as soon as it has been in stand by for an hour it is back agian. just like it cools of and something goes wrong. I have not had the possibility to check if it is also there on Powerling speakers, have you tryed it?

not much of help to you, but I hope that someone on the forum can help us both now.

//Goran 

Hi Goran,

thanks for the reply.

Yeah, similar if not the same problems.  I am following the same procedure in order to use the BM.  I am leaving it in mute for about an hour and then I can use it!

Sorry but I don't know what you mean with "I have not had the possibility to check if it is also there on Powerling speakers, have you tryed it?".  Could you please explain me?  What is Powerling speakers?

Cheers,

Vassilis

Hi,

sorry that should be Powerlink, and that is the connection for activ speakers. However I realised that the connection does not exist on the 3300. so nothing that you could check...

really, no one who recognise the issue, and in opposit to me have experianse with a solution??

If it is not the transformer, then humming could be caused by the main power transistor which regulates the voltage directly after the bridge rectifier.

If the technician replaced only that transistor without replacing the adjacent capacitors, then you will probably have the symptoms you are describing.

When power transistors are replaced, the capacitors must be replaced as well, otherwise the problem returns.

Menahem