Whistle on laptop's speakers

[DrumSergio]

Hello, my friends.

I am experiencing a annoying whistle of more than 10kHz (don't know exactly, but very high-pitched) on the speakers of my laptop. It's very strange, and I will tell you why.

When I move the mouse it doesn't sound. When the mouse is stopped, it instantly becomes again audible.
Also when I reproduce anything in the computer, such as a mp3, with all the volume turned down, I can't heard that whistle. When I stop the mp3 player, it becomes again audible.

Another thing to have into account is that connecting the headphones doesn't make any difference, the whistle continues to happen from the speakers (when I plug in the headphones, it is supposed that the sound will only come to the headphones, but that doesn't happen with the whistle)

It is a very strange thing... hope you could help me, guys, to repair it. Is it from the sound card? It is external radiation? I don't really know

Thank you a lot
Sergio

 

[ssc456]

Does it only happen when the laptop is plugged into the mains? Does it happen on battery power? I've had this kind of issue before and it turned out to be a bit of a dodgy earth situation.


Try updating your sound card drivers.

 

[DrumSergio]

Thank you for answering.

It happens plugged in and also running with only battery. No difference. I've tried right now.

I updated the realtek drivers but there's no difference..

Thank you

 

[setishock]

You know that's just so odd. My desk monitor has developed a annoying little noise. Mine is the PWM module, for the LED back lighting, has slipped out of the factory calibration due to getting banged around when I moved.

In your case my not knowing brand name or age of the laptop, I'm going to make a general assumption.
It's the back light inverter. They make the most annoying whine if it's getting old or on it's way out. You don't hear it when you have your headset on because it's just blocking out the noise. It's not coming from the sound system.
Inside the inverter is a push/pull transistor setup, a transformer, and a filter capacitor. If the cap or the transformer (or both) develop a problem, you hear it whine. The 10Khz is about right. You sense it more than hear it. And it is nerve grating.

The fun part is getting the bezel off the front of the monitor panel to replace it and getting it back on. If it's under warranty send it back in to be serviced. If not a shop can handle it pretty quick.
Or you can do it yourself.