Whine when playing video

[Samarium151]

Another day, another attempt. This time, I added the following circuit instead of L11:

And while it does not solve the problem entirely, it significantly reduces the noise down to an acceptable level. There is enough space on the PBP to fit this circuit, but it's still three components for one. Yet, I don't really have any other idea at the moment. Well, apart from messing with the SMPS chip, but I don't feel like risking to fry the entire board when I only have one to play with.

It’s cool you have made progress.  I don’t have hardware in hand yet.  I haven’t seen any measurements of the frequency.    I think  could measure a put a high pass filter on sound output. Though your solution to try and smooth the ripple at the putative source is more elegant.