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Thread: Power supply buzzing when pc turned off

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    Default Power supply buzzing when pc turned off

    Hello!

    When my pc is turned off (power supply switch is still on), my power supply emits a buzzing sound, which can be heard from about 1.5 meters away, when the room is quiet, for example at night.
    When the pc is turned on, the buzzing sound seems to disappear, at least I cannot hear it while the others fans are working.
    The psu is the Corsair RM750x, I just bought it. It is connected to a power strip, if that matters.
    It bothers me, because this psu is supposed to be pretty quiet unit.

    Should I get the unit replaced? Is this problem eligible for RMA?

    Rest of the system:
    ROG Strix Z390-E
    Palit RTX 2080 Gamerock
    i7 9700k
    HyperX Predator DDR4 RGB 16 GB

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    Quote Originally Posted by metyko View Post
    The psu is the Corsair RM750x, I just bought it. It is connected to a power strip, if that matters.
    Is the power strip plugged into a grounded outlet?

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    I don't know if its grounded or not, excuse my incompetence, I'm including some pictures about the plug and the outlet.
    I live in Europe, and the house and the electric wiring in the walls are quite old. Also, when I plug my android phone charger in the outlet, it makes a quiet high pitched sound.
    https://imgur.com/kfnebhm
    https://imgur.com/cPkXZQ1

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    Yeah. Pictures don't tell anyone if your outlets are grounded. The outlet has the proper pins, but who knows if they're actually grounded on the other side of the wall. To find out, you actually should use a tester like this:

    https://www.amazon.de/Bewegliche-aut...dp/B07LH3J4WZ/

    It's really a cool tool to have handy!

    At any rate: The buzzing isn't damaging. It's the PFC choke coil vibrating. Some units are louder than others, so if the noise actually bothers you that much, you could try RMA'ing the PSU and see if another unit is quieter.

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    Thank you for the help. I might buy this tool to check if it's grounded. Let's say it is not, if I move to a new apartment, where the outlet is grounded, this little buzzing might disappear? Also, why is it only buzzing noticeably, when the computer is 'off'?

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    Quote Originally Posted by metyko View Post
    Also, why is it only buzzing noticeably, when the computer is 'off'?
    Well.. the PC isn't "off". It's in standby. There's always power going through that coil. Just at the lower loads of +5VSB, the frequency of that energy is at a lower, audible frequency.

    What all do you have plugged into your PC while it's in standby that would still be drawing power from the +5VSB? You could do an experiment of unplugging those peripherals or plugging more in to see if the frequency of the buzz changes.

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