[sloober]

Another German radio. I have fixed a few of these recently and they all have a very similar look. A Tonfunk I did has nearly the same dial and buttons. You would be smart to replace the old caps. Were not many in the one I did, but it may vary.
The switches can be very finiky, and if they break, you're done. You need to clean all the dust out of it and spray switch cleaner into the switches inside. Are they poping back up on you? After cleaning and lube it should be better. As for the side speakers, I would look inside to see that they are connected. Some use electrostatic speakers. It could also be a cap for the crossover that has failed. If there is one you could short across it to see if you get sound. Then just replace it. That is a pretty radio! John