Found that the S-MIX chip at U10 has a little bit of a problem: visible physical damage. Might explain why there is no sound. It’s amazing what you can find when you really focus on the problem. Even still, it’s good to have new capacitors on there.

I expected the fresh capacitors to stay leak-free for at least 15-20 years. That is not a guaranteed lifetime; it depends on the parts and their operating conditions.

Sources