MX4000 speaker problem

12 replies

My lovely black MX4000 has been allowed down from the attic and into the bedroom by SWMBO.

Unfortunately, only the left speaker is working. It is not due to balance settings, I've tried that. The MX4000 has been moved from Copenhagen to Oslo and been stored since then and I am not certain if the right speaker worked before.

Is this something that could be caused by bad capacitors or should I expect the speaker to be faulty?

Thanks 🙂

I have had problems in the past with the plug/socket on the main board where the speaker connects.

salut

do the speakers have separate plugs or is it just a double type - if separate try reversing the plugs if the one cahnnel is still down could be the output transistor amp - had this prob with a 5500 - easy task replacing if you have a so0lder sucker etc

tony s

Got home from work and unscrewed the back of the MX4000.

Locating the speaker plugs was easy enough. Indeed as you proposed, Graham, one plug wasn't entirely in its place.

Unfortunately that didn't do it - turns out the speaker also has foam rot 🤔. Strangely, the right speaker was far worse than the left one and as the right speaker is still not working I fear that it needs to be replaced completely.

In my experience the speakers usually have foam rot but it does'nt stop them from working. I suggest a PM to nobby who has much knowledge of MX's.

Another thing to try is to switch the sound output to MONO and see if both speakers work this tests out the Nicam board. I freely admit that I have learnt all this MX stuff from nobby so you are better off dealing direct with the main man!

hi

as previously check the speakers by swapping the plugs if same channel down ie left original and right after swap then its likely speaker or try each plug in working channel

tonyb s 

Thanks, Tony!

I will definitely try and swap the speaker plugs. For some odd reason I didn't try that yesterday 😂

I will contact Nobby with any additional questions. Thanks to you too, Graham!

I had an MX5500 with same fault!

 But my guess...  MX4000 + storage = dry joint.  Is there sound in both channels from the headphone output so we can eliminate everything to do with reception, audo demodulation + decoding and preamplification.  Leaving only the power amp stage (+ associated Power Supply) and connections.  Having said all that, to test these things then you need the TV set ON.  AND if you're not an experienced engineer then running the TV with the back off is a hazzard (think people sometimes forget on here), so stay safe. 🙂

Will check the headphones tomorrow 🙂

I am the first to say that I shouldn't try testing anything with the back off and the power on, I am very well aware of my limitations in that field 😕

or
BeoWorld Gold Membership card
Join BeoWorld

Register to access the forums, reference material, and exclusive member benefits — including our monthly prize draw.

Become a Member

December 2026 Prize Draw

Gold Members Only

As a Gold member you're automatically entered into our exclusive prize draw — your chance to win iconic Bang & Olufsen products. A unique benefit of BeoWorld Gold membership, every draw brings a new opportunity to win something special.