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I have a Lenovo Thinkpad Edge E520 that emits a high pitched whine from the top lefthand area of the keyboard when a 2.4ghz wireless USB mouse is inserted. The sound is a lot louder while on battery power. The noise goes away after removing the mouse, and inserting it causes it to start back up again.

Disabling "CPU Power Management" in the BIOS solves the problem so I assume it is related to CPU sleep states as I've read around the internet. I don't want to leave this disabled as it decreases battery life.

I posted on the Lenovo forums and they were not much help. I had the exact same model that exhibited this behavior and I exchanged it for a new one which has the problem as well. Anybobdy have any ideas?

edit: The sound lasts as long as the mouse is inserted and the cpu is relatively idle. Also, the noise occurs with multiple 2.4ghz wireless mice I have... bluetooth mouse does not cause issue.

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  • Sounds like the usb device is drawing too much power. Have you tried using another usb mouse adapter? How long does the sound last?
    – iglvzx
    Jan 2, 2012 at 2:16
  • Sound lasts as long as the mouse is inserted and the cpu is relatively idle. Jan 2, 2012 at 2:19
  • This sounds an awful lot like capacitor whine. I'm unfamiliar with the capacitors used in laptops, so I am not sure if they fail in the same way that larger electrolytic capacitors do.
    – cmorse
    Jan 2, 2012 at 3:06
  • There is no fix. Same happens on my T500, and on an Acer laptop (friend of mine). Oh, and a Dell Latitude. So, I just gave up.
    – Apache
    Mar 15, 2012 at 16:38
  • Does this mouse have a "high polling rate" ? The driver may be preventing the cpu from sleeping, or maybe waking it up more rapidly than expected, causing the cpu to shift frequency often, which would create a whine. Disabling power management would minimize the cpu freq shifts, and quiet the whine. Remove the driver, shouldn't need it anyways, or see if there's an updated driver.
    – lornix
    Jul 6, 2012 at 8:56

1 Answer 1

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I'm not sure what you mean with a "whine", but it might be the laptop fan. When you insert the mouse, the PC will require more power, which will generate more heat, which will require adjusting the fan speed. Disabling power management might have the same effect.

If the fan has a slight imbalance, the change in speed might cause it to go to a resonant frequency where it will vibrate.

If this is the case, the fan will have to be replaced.

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  • how much power do you imagine a mouse could conceivably consume?!? It's USB based, so it HAS to be rated for 500mA or less, and it's wireless, so the power consumption is likely LESS than 100mA and more likely less than 50mA since it only has to transmit and receive a low-power radio signal. {Grin} Fun! Fun! Oh.. my mouse? Yeah, it gets warm.. keeps the apartment toasty in the winter though.
    – lornix
    Jul 6, 2012 at 8:53
  • Lol, point well taken. Don't know what I was thinking when I wrote that... Aug 30, 2012 at 17:15

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