laptop screen gives annoying high pitch

grx

I've just set up gentoo on my dell inspiron 8600, and I've noticed that the screen gives a really high pitch whine or whistle when it's turned on in linux, but it's not there in windows. It happens both in console and X modes. Is anyone familiar with this? I'd imagine its some configuration setting that's off, but I don't know where it would be or what it should be set to. I do have the nvidia drivers installed (using GeForce 5200 on this system). I'm not sure what else I could post that would be useful, so if anyone has an idea, let me know what information I can get you.

mkzelda · n00b Joined: 22 Aug 2004 Posts: 32

I have a laptop that does that. Its actually feedback caused by poor design. The microphone is on the screen and the speakers are just under it. I just disable the microphone. If this isnt actually your problem and really is the screen than sorry, ignore me.

grx · Posted: Sat Apr 02, 2005 5:43 am Post subject:

alsa mixer shows the mic is already muted, and the sound is still there.

Also, I've noticed that it may not come from the screen, but from the upper left corner of the laptop itself. It also disappears when the machine starts working, and seems to come back when it idles. (Not exactly, but more or less like that.)

finr · Tux's lil' helper Joined: 24 Feb 2004 Posts: 126

Yep, I have experienced this too - with my Inspiron 8600c as well as with another notebook from HP. It also seems to disappear as soon as an USB mouse is plugged in. I suppose that without some DC/DC converter is driving too little current and therefore working at a frequency which is audible. As soon as more current is drawn from it (be it because the system load increases or an external device which draws current is added), its switching frequency rises and goes past the audible area.

grx · Posted: Sat Apr 02, 2005 1:10 pm Post subject:

Is there some way to fix this?

finr · Tux's lil' helper Joined: 24 Feb 2004 Posts: 126

If it's really a DC/DC-Converter working at an audible frequency I guess there's no easy way to fix this besides adding load like a mouse or whatever.
You could always drop Dell an email though.. If you do, please report back here

rang3r · n00b Joined: 09 Jun 2004 Posts: 25

Check your ACPI settings. I had this problem until I removed the processor and video from ACPI in the kernel. I am not 100% sure which fixes it, but I believe it is processor.
_________________
rang3r

grx · Posted: Sat Apr 02, 2005 9:21 pm Post subject:

Is there any functionality change I should be aware of if I remove either of these from ACPI? I'm betting it's the processor as well--that seems to be where the sound is actually coming from.

grx · Posted: Mon Apr 04, 2005 3:32 am Post subject:

OK, I'll confirm that--I changed the ACPI processor handling to a module instead of being built in, and the sound has stopped. Does anyone know why it was happening in the first place? I'm kind of curious to understand what the difference is a little better.

ercxy · n00b Joined: 26 Apr 2004 Posts: 55 Location: MA

Check this;
https://forums.gentoo.org/viewtopic-t-9754-highlight-8600.html

you are not alone, my laptop dell 8600c does same weird sound .. You can get rid of the sound
by changing internal frequency of kernel or something like that.
Note:This sound problem only happens if you have 2.6.x kernels, 2.4.x kernels don't have this problem..