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my first post here, so hope it's on-topic for the forum.

Straight to the point... I have RPi 4-4GB running Astroberry for astro-imaging. The RPi is in the Argon ONE V2 Raspberry Pi 4 Case, and the power supply is the official UK white Raspberry one, all purchased from pihut. I noted originally that there felt like 'buzzing' when touching the case and it's never got any better. When running an imaging session with my telescope, the RPi is controlling DSLR, tripod tracking and a guide camera, all of which when touched feel the same. This can't be good!

I've searched everywhere for other issues and the only one that comes back is suggesting power supply issues. I have this issue with 2 genuine RPi supplies (one belongs to the RPi400, and the other purchased for this), and in 2 very different locations (work and home), so doubtful of a mains issue.

Thinking of debugging further, I took the RPi out of the case and connected to the 'guide-camera' only (USB-C), and the same feeling is apparent on the camera case. So I'm inclined to say it's the RPi itself with the fault, but is there a way I can stop the issue without just deciding that I have to write off the board? It's been in the Argon case purchase, and these devices are regularly used outdoors without issue.

It's most annoying when looking through the camera viewfinder during setup and getting static shocks on nose!

Thanks for your help in advance!

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This has NOTHING to do with the Pi.

This is a common issue with unearthed devices. TV and other audio/visual devices are common offenders.

The official Pi supplies (also virtually all plugpack supplies) are Double Insulated. This means they float WRT earth.

It is possible (probable) that there is some capacitative coupling from the mains to the (nominal) 5V/Gnd, although this may be unnerving is not dangerous. It can be avoided by using an earthed supply.

If you disconnect your Pi from all other powered devices I suspect the issue will disappear.

It is more likely that some device you have connected is the ultimate cause. (I have noticed that if I connect my Pi or indeed any other computer to my TV there is often a visible spark). Mains interference filtering on higher power switch mode supplies exacerbates the problem.

If you bond ALL devices to a common Gnd (preferable star connected to avoid ground loops) you should have no problems.

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  • Thanks Milliways, My only doubt here is that the case (containing only fan) is still buzzing without anything touching it (other than my finger!) Plugged into a genuine adapter (with insulated earth pin), I'd have thought no earth to case might be the issue, but makes no sense with the genuine adapter. I agree that it's not dangerous, just frustrating! Without breaking the rules of the forum, can one get earthed RPi supplies? When you say 'star connected', what do you mean here? Thanks again
    – pete
    Jul 12 at 12:54
  • @pete As I understand it, star grounding means that all grounds attach to one common point. Think of six different leads in a circuit that all come together at a point in the middle, so they resemble a star. Jul 12 at 23:04
  • @pete star connected just means connected via a star configuration which has no loops (as distinct from mesh). Ideally this utilises a single point. In fact this is somewhat of an art. NOTE this will do nothing about tingling, but is for other reasons. AFAIK there are no plugpack with Gnd (but this may differ by country). I use a 10A 5V switch mode supply to run many devices, but many of these need adjustment/modification to get the 5.1V for Pi.
    – Milliways
    Jul 13 at 0:44
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If I use one of the USB ports, chop up a USB cable and take the black (gnd) to each of the mount, guide-camera and main camera (the parts of the system that feel 'electrified'), would this ground everything to the RPi and eliminate the issue?

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