Es-9 power surge problem

[Nonlocal]

Hi, posted something about this problem I’ve had with my es-9. Found out I should probably post it here

viewtopic.php?f=16&t=244877&p=3465477#p3465477

Essentially, I received a warning on my computer today informing me there was a power surge coming from the es-9. Was wondering why this might occur? Details about my setup in the original post

Thanks!

[os]

Never heard of that happening before. Keep an eye on it and let us know if it happens again.

[Nonlocal]

Thanks for letting me know! So far it was a one time thing, other than that instance, it works gloriously. Will let you know if it happens again.

[Nonlocal]

Never heard of that happening before. Keep an eye on it and let us know if it happens again.

So to update, I did encounter this issue again. It seems to occur when plugging and unplugging headphones while the unit is turn on. If I remove the headphone jack with the volume turned completely down then no power surge occurs, but when I do with volume up at any level, it seems to send a surge through the usb connection.

[os]

Interesting, thanks.

[Nonlocal]

Just wondering, why do you think this is happening? I’m wondering if the 12v rail is leaking into the USB port via the headphone jack for some reason. Really just don’t want to cause damage to my computer or the unit. Thanks again

[os]

I can't think how that could happen. The ES-9 doesn't draw power from the USB connection or provide power to it.

I wonder if it's actually a grounding issue.

[Nonlocal]

I wonder if it's actually a grounding issue.

Grounding issue with the unit or with the case? I tried switching to a different case, and the problem persisted. Also, if it’s useful information, I just discovered it does the same thing when unplugging the usb-c from the unit.

[os]

I meant grounding between the computer and the case(s).

[Nonlocal]

I guessed that there may have been a ground loop because I had my laptop plugged into the same surge protector as the case, but it still popped up after I removed the charger, and when I tried a couple different outlets.
Strangly though, I came home today ready to test a couple other things, but now I can't get the problem to repeat. Which I suppose is a good thing, but I'm just not sure what I did differently.

Anyway, thanks again for you help and time! It's much appreciated