I was in a similar situation as you – purchased a BS5 + BM5 combo, where the Beomaster was only usable as a power supply. My intention was to make the panel work with a Raspberry Pi and recreate the user interface on that (long story short: it's totally possible).

The Beosound 5 panel can indeed be connected to a computer for use as a monitor, but it requires you to manually configure the output to send an appropriate signal to the display. My understanding is that the panel doesn't "tell" anything about itself to the computer for this to happen automatically. I wish I could be more helpful here as I've only done it successfully with the Raspberry Pi, I never got it to work from my Mac, for example.

The USB device in the panel should be recognised, in that it will appear in the USB device tree (I've tested this on a Mac). However, it is expected that the controls will not do anything out of the box. The communication protocol of the panel is very simple but proprietary, so you would have to write a piece of software that communicates with the panel and translates its input into desired events on your computer.

Hi! Thank you so much for your reply!

Based on it, I believe my Beosound 5 is faulty. It's not coming out of standby whatever I do. I've stripped it down and removed the PCB - I've just noticed that one of the resettable (poly) fuses is open circuit. I'm going to try replacing it. I have one of a reasonably suitable value, but it's a lot bigger than the original, so I'm not sure how successful I will be!

I have ordered another Beosound 5 anyway - should be here in a few days. I just like fixing stuff!

In other notes - I've seen ideas around connecting the Beosound 5 to a Raspberry Pi - I've seen some code for interpreting the protocol. I'm a software engineer by profession, so working with that should be no trouble!

I'll keep you all posted - thanks so much to @tph for replying - my main desire was to definitively tell if my Beosound 5 was faulty.

Andrew

No - it's dead, Jim :-(

Interestingly, the board has a 3.3v regulator - before I replaced the polyfuse, it was not working. It is now working, but the board is still dead. I suspect something major has failed on it. 

As an aside, the controller wheel/volume knob, etc., is an engineering marvel. Beautifully machined. Such smooth operation and intricately designed. It's a work of art!

Andrew

And another comment...

I've just looked up the specs of the display in the Beosound 5  - it's just a 10.4 inch LCD. Might be able to replace it with something like this: https://www.ebay.co.uk/itm/265340214525?hash=item3dc7825cfd:g:vmkAAOSwAHFhWCAx

Or even drive the display via LVDS, and power the backlight inverter otherwise.

And - the position encoders on the rotary wheel are standard, off the shelf items. It wouldn't be beyond the realms of possibility to engineer complete, open source replacement electronics and firmware for the Beosound 5. Imagine modern electronics inside the old B&O case?? Is anyone interested in joining me on a project? Would need electronics/PCB design skills and/or Arduino programming skills! I have all these skills but really strapped for time...

For now I think I'm just going to try interfacing to a standard Beosound 5 and developing my own code for it... I have an interesting idea for using it as a control panel but I'd need it to last for another 20+ years!

Andrew