I hear "futuristic" crackling nosies that are very familiar from movies. Not sure if it's coming from the pi or the power supply... the same sound is coming from BOTH the power supply and the pi. I swtiched to using a long usb cable to test. Even more interestingly, two different power supply have a different quality to the crackling sound (one is more "grainy, with longer pauses at random times") and each pi seems to have the same type of sound as it's power supply.

What are those nosies and are they indicative of power inefficiencies/issues?


  • My Pi Zero W sometimes shuts down unexpectedly
  • Also, worried about "Undervoltage detected!" kernel messages, yet that's probably unrelated
  • I'm using USB-A Addon Board V1.1 USB Connector Expansion Board For Raspberry Pi Zero v1.1 - maybe there is an arc at the connector... removed Addon from my setup, nothing changed
  • My power supply is https://www.amazon.com/gp/product/B01385COIE
    • Input: 100-24V 5060Hz 0.3A
    • Output: 5V DC 2.4A
    • It has 2 USB slots and I'm using both to power 2 pis - one slot is labeled "For Cell Phone only" and the other "For Cell Phone and Tablet"
  • 2
    Get a better power supply! If you can get rid of undervoltage problems and you still have issues, come back with more info. What are you doing? Running code? Driving devices on GPIO? Do you have USB devices drawing power? Apr 3, 2019 at 16:21
  • 1
    Out of curiosity, where did you get your power supply? Does it have a mfr name or model #, or anything that might identify it?
    – Seamus
    Apr 3, 2019 at 20:11
  • I edited the post - added more info Apr 4, 2019 at 0:51
  • 1
    Not sure if it's coming from the pi or the power supply use a longer cable ... then you'll be able to tell which is making the noise - I'd say it's the power supply Apr 4, 2019 at 1:14
  • 1
    If you take a laptop power supply, and press your ear against the case, is that the sound you hear?
    – crasic
    Apr 4, 2019 at 6:12

1 Answer 1


yet that's probably unrelated

That's definitely not unrelated. If the pi says "Undervoltage detected!" it means "Undervoltage detected."

Unexpected shutdowns are usually caused by a bad power supply.

And the crackling is most likely coming from the power supply. It's probably happening because the pi is putting too much stress on the power supply.

So get another good power supply that is rated for at least 2A and if the problem still persists then edit your question and add some more details.


If the sound you hear is actually "crackling," that's not normal. It probably means something is shorting or arcing inside the power supply (as I said above, possibly because of too much electrical stress). If what you here is just whining, or buzzing, that is normal depending on the type of power supply. Basically, the electromagnetic properties of the electrical coils and inductors inside the power supply are causing the coils themselves to vibrate. Here's another explanation.

  • I swapped to a different power supply - will take 48 hours to verify that there are no crashes. What is the crackling sound called or physics behind it? Is it an arc? Apr 4, 2019 at 0:46
  • 1
    @AleksandrLevchuk I added more details to the bottom of my answer. Apr 4, 2019 at 4:09

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