One channel of sound from MMC4 Cartridge - Fixable?

4 replies

I recently came across an RX2 turntable and was able to fix one problem to get it working, but there's only sound coming from one channel. Rotating the cartridge 90º in the tonearm switched which channel was working, so it appears that the cartridge is the culprit. Spending a couple hundred euros to have someone refurbish it isn't an option, so I'm wondering if there's anything I can do myself to get this working? Soak the whole thing in alcohol? Disassemble and clean it? Haven't had any luck searching for a repair tutorial, and it's not clear how the cartridge comes apart. Any help appreciated.

Thanks!

It could be that the pins are loose. I have had this happen to one of mine. A small tap with a light hammer on the offending pin was enough to fix it and was accompanied by a resolve never to take it off the arm ever again! If it doesn't work, which it likely won't, you have lost nothing. Taking them apart is very tricky and appears to require sawing into the body.

My B&O Icons:

BeoCenter-9500.png BeoCenter-9500.png
Beoremote-Beo4.png Beoremote-Beo4.png
Beovox.png Beovox.png
Beovision-11.png Beovision-11.png
Beotime.png Beotime.png
Beosound-Stage.png Beosound-Stage.png
Beosound-Moment.png Beosound-Moment.png
Beosound-5.png Beosound-5.png
Beosound-2.png Beosound-2.png
Beoremote-One.png Beoremote-One.png
Beoplay-Portal.png Beoplay-Portal.png
Beoplay-Earset.png Beoplay-Earset.png
Beomaster.png Beomaster.png
Beolit.png Beolit.png
Beogram-400x.png Beogram-400x.png
Beocenter-2.png Beocenter-2.png

Thanks for the suggestion Peter, I'll try it.

Anyone else taken one of these apart or fixed a one-channel sound problem?

Repair of a dead channel is very difficult job that professional cartridge rebuilders with equipment and experience can’t always succeed at.

I’d send it off to be rebuilt.
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.