There’s a guy in Denmark offering a repair service for IcePower-equipped speakers. You can find his website here: https://www.juhltec.dk/
The list price for the repair of a BeoLab 3 is 1620 DKK which equals to 216€ including VAT.
I don’t have any personal experience with him, but he is often referred to in different Bang & Olufsen groups on Facebook when it comes to IcePower-related problems.
If you have the courage to do some troubleshooting yourself, you could try swapping the modules between the working and faulty speakers to find the faulty module. But be aware of the risk of damaging the working modules! It shouldn’t be done without inspecting the modules for obvious signs of damage beforehand. And it is essential to take precautionary measures to prevent electrostatic discharge.
If the IcePower-modules are faulty, it would probably be cheaper to buy a BeoLab 7-1 or 7-2. They are equipped with three of the same IcePower modules you’ll find in one BeoLab 3. There are different versions/revisions of the module and I’m not sure if all of them are interchangeable, but I have three BeoLab 3s with faulty IcePower modules myself and have succesfully used a verD module in place of verE for troubleshooting.
.
