I agree.
Most likely to be a problem with the Beocenter 9300.

I seem to remember that I had a non-working BL1000 as well some years ago and remembered to have read, that the processor can lock up. To reset it, you have to discharge the remote completely. The caps inside will still hold a small electrical charge even when the batteries are removed, so to do this, remove the batteries and short the terminals with a short piece of wire. Take a look

I have a BC9300 and years ago my BL1000 died. But I recently got to playing with again and realized the battery contacts weren't firmly touching the end of the batteries and there was some corrosion. So I scraped the corroded surface off and I could verify it works, and used my phone camera to see the infrared LEDs since cameras are generally sensitive to that part of the spectrum we can't see. 

Thank you everyone who has replied. So far the IR isn't working - as not seen on an iPhone - there is one battery connection broken which needs soldering and after that I will see what happens. The handset has always given such pleasure as the balance is so good and the design is brilliant - so I hope I can repair it.

The soldering worked and now the remote is working properly. The idea of using the iPhone camersa to see the IR signal is brilliant and was really helpful.