Hi Guy and thank you for your reply.
I followed the B&O manual. It says that the BeoSound Century music system can be controlled with a remote control. To turn on the remote control function, press Standby, Sound, 1, Store. The number 1 is briefly displayed. So far everything works. Then I followed your recommendations. First the test with the iPhone camera and it confirmed that the Beolink 1000 fires. Then I pressed Standby, Sound, 1, Store on the remote control. However, nothing happens. The Beo4 also works but also here, nothing. So it should be the Century’s IR receiver, right? Is it possible to see the part or get at it somehow? It will probably be difficult to get a replacement part. 🙁
By the way, my device only came with the spacer and no top wall bracket. Maybe the question came up here in the forum before, but is there a technical drawing (including the twi hooks) of it so that you can 3D print the part (or at least create a template for it)? A replica by the metalworker would of course also be possible.