I am trying to figure out how to connect the Beocom 3 to a headset using the 3.5mm jack. When I use 3.5mm jacks, mono or stereo, it does not work and the phone reports that no headset is connected. If I pull the plug about half way out of the jack, the phone reports that a headset is connected and I get sound in the headset, but the microphone can only barely be picked up.

It would seem that the 3.5mm jack is not a standard connector. Anyone have any knowledge of the proper plug for this or other ways to make it work?

I have the same phone.   I've never tried a headset with it —oh the speakerphone is so, so very good—, but I always expected it will only work with some rare B&O headset...

Please post your results when you find out.

The STANDARD 3.5mm jack actually has two (2) standards, Mono or Stereo.

As you have said that if you pull the plug out about way, then the phone reports the headset connected, means you have the wrong jack.

A Mono 3.5mm jack has one black band on the plug and a stereo has two.

Below is a picture of a stereo plug, notice the two black insulating bands

Thanks for the responses. I figured that the mono/stereo issue may be the problem, and so went out and bought a mono adapter. Unfortunately, the phone behaves the same way, reporting that the headset is disconnected if it is pushed in all the way.

Bit of a shame. Love the phone otherwise but this is becoming a bit of a deal breaker for home-office use.

If that is the case, then the only conclusion we can draw from your feedback is the jack socket in the phone itself is damaged.