Assuming you have done all the cable swapping initial checks and from your symptoms, I would suspect a main power supply fault.

As far as I know, the red/green led runs from the standby power supply so that is no real indication that the amplifier is receiving power.

You will need a B&O engineer unless you are qualified to dismantle the amplifier module.

If you are comfortable disassembling the speaker there is something you can check.  If you take the grill and speaker cover off you will see that there are two modules, the power supply/amplifier (bottom) and the speaker enclosure (top)  If you take a razor knife and cut the foam strip that runs the entire length of each side of the face of the speaker you can remove the power supply/amplifier module.   This is accomplished by removing the 6 metric allen screws in the module.  On that module the bottom portion is the power supply and the top portion is the amplifier.  The custom equalizer board sits perpendicular on the amplifier board.  This board can come loose as it is held in the socket by double sided adhesive pads on each side of the PCB (printed circuit board).  During transport this board can come loose, just push down on each side to ensure it is properly seated.  This is a common problem.

Thank you both for the quick replies.

I have no problem with tearing apart the speaker to get to the bottom of the issue.  My only concern is (since I have not done it before) getting the grill off.  It seems so delicate, and being a major point of the cosmetics I would be a little nervous about that.

I dont plan on selling these speakers so even if I mess it up more, it would still be a trip to the repair center.  

If you can give me any further instructions on getting the grill off painlessly I would appreciate it.  The service manual did not give me much to work with besides pry it off.

Thank you

Well the equalizer board was not the problem.  It seemed pretty well anchored to the amplifier and the speaker still does not work.  Any other suggestions to help me out?

Thanks

Did you ever figure out your issue? I would be interested in purchasing your broken 8000 if you didn't get it working.

No, I never did get it fixed.  I live nowhere close to a service center and have not been close to one recently.  I might be interested in parting with it, actually.  

I have a pair of BL 4000, had them connected directly to my wall power jack, one of them sometimes showed green light, but no sound.

I brought it to B&O Mexico city, no solution, but a fine cross scratched on the top of the fine polished aluminium.

Sometime later I connected all my speakers to a nobreak powersupply, and after that no problems. We have a lot of brown and black outs here in our area, sometimes the power is down to 85-90 volts, the funny thing is that only one speaker failed, I also had two BL 8000 connected at the same time, but no problems.

So check your power, or try with a nobreak

If you are still having a problem...

When you power up ypur 8000's do you hear the relay inside the speaker click?

When you had it apart was the internal foam sticky and falling apart?

No, I dont recall the relay clicking on to tell you the truth.  The foam was a bit sticky, but was not falling apart too bad.  Have an idea?