You shouldn’t be able to feel any electricity unless there is a ground loop. 5v isn’t enough to break your skin (25v is) . That buzzing sounds digital. Like your sound device is on the same pins as the encoders or something.
I’d double check the cables inside.
Strip in down to just the Pi and see at which point ( if any) the sound goes away.
Ups! It’s really a big noise, @schrectacular. Not normal at all …
- The frecuency of the base clicks seems to fit the status bar refresh time (0.2 s), although nothing is displayed, so display doesn’t seem to be the problem.
- Extra noise is added when you move the encoders (and the IRQ code is executed).
- When the question dialog is shown, refresh is stopped and the base click stops.
All this (especially point 1) makes me suspect that the power source (or the power cord!) is not performing as it should. I would try with a different/better one.
If it doesn’t work … have you tried to unplug the audio input harness?
Regarding the connectors shields, there shouldn’t be a problem if they touch the aluminum case. In fact, it should be good because shields and case must be connected to ground (and they are!).
Regards,
I unfortunately can offer no solution cause my problem was fixed only when I changed my Rpi to an Rpi 4.
My suspicion was that there was something bad in the Rpi 3. Bad soldering somewhere causing the grounding problem.
I had a similar issue with things toucing the case, I had to isolate the screen from the case.
I hope this helps.
Wow amazing to wake up to so much help!
Ok so I figured it out… it was my fault and currently I’m still to ignorant to figure out what I did, but there was a variable I didn’t tell you about - I had this plugged into a homemade amp. And it turns out THAT was the problem. When I use a proper commercially purchased practice amp all is well.
I still get some slight popping when I use this amp, but soldering a 330pf capacitor from input to ground solved almost all of it. I still hear some sliiiight popping, but it’s the amp being weird.
Thanks all!
Well thats good to hear, but this does, of course mean I can go …
I’m so confused what does that mean?! I might strip the thing down to the RPi one day, but I’ve had the thing open and closed so many times since I got it a few days ago, I’m ready to just leave well enough alone and jam.
I will hop back on this thread if/when I end up cracking the thing open. I also have another RPi v3 so maybe I can try that too, see if it makes a difference.
Oh and if you want to my amp you can check it
here.
Thanks again for the help.
Hahaha that’s amazing. I’m REALLY glad I uploaded that video now… 
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