high pitch noise- not fan/speaker/lcd.

[some_guy_named_matt]

hey guys, i dont know if im just now noticing it, or if it's just started to occur [im guessing the ladder as ive been running this distro for weeks now], but recently ive noticed a high pitch squeal coming from under the keyboard on my laptop [dell inspiron 1521] and its driving me crazy- i had to switch to vista last night [quad boot] cause i couldnt stand it anymore. >

some things to consider:
- i know its not the fan, because theirs noise when the fans not running
- not the monitor, as the noise clearly isnt coming from there.
- not the speaker, as i can hear it over music- even with the headphone jack plugged in.

i did recently have an issue with the wireless, for some reason it didnt auto-start the network manager, but i got that working. before then, i didnt notice any noise, so maybe theres a connection there.

EDIT:
also, it seems to be quieter when the hdd is under load, like copying large files, or something of that nature, which is leading me to think maybe its the hdd itself theres no noise when running windows on the same hdd, so it cant be the drive. it seems to start squealing once the desktop loads.

i hope i supplied enough information, i dont think system specs are vital to this type of problem, from what i can tell its a pretty broad issue to some linux users.

[Telengard]

Re: high pitch noise- not fan/speaker/lcd.

All I can do is guess at the problem without having the unit in front of me. Even though you claim it is not a fan, I would still suspect fan noise first on a laptop computer. It is the most common source of noise on laptops. There may be one or more internal fans which you normally would not be aware of.

If in doubt, take the unit in for service by a competent professional. That kind of noise coming from a laptop can't be good. It is quite unlikely that you will find satisfaction by posting about the problem in a forum.

[some_guy_named_matt]

Re: high pitch noise- not fan/speaker/lcd.

well its strange that it doesnt occur in windows, and that it's just started. its the end of the year, about time for a clean slate on my drive anyway. just hoping to get this fixed alternatively.

[Telengard]

Re: high pitch noise- not fan/speaker/lcd.

I remember there used to be some problems with fan speed control software. Try searching the forum for fan speed and see if any of the hits you get sound similar to your problem.

example

Remember, I'm just guessing here. No way can I tell from across the Internet what the problem really is. If the fan is making the noise then it definitely needs replaced, regardless of any possible software problem.

[some_guy_named_matt]

Re: high pitch noise- not fan/speaker/lcd.

i appreciate your input, ill keep looking.
i downloaded and booted the live cd for 9.10, and no noise.

this is weirddddd lol. :P

[Ole Juul]

Re: high pitch noise- not fan/speaker/lcd.

If it changes under load, perhaps it's the PSU which will be using a high frequency for conversion. I think they normally use frequencies over 20k, but you never know. You'd have to operate it while opened up to diagnose that. Since you're asking here, I'm guessing you're not too comfortable with electronics. You'd get better info on an electronics forum. That said, my intuitive guess is that you just started noticing it and everything is actually OK.

[Telengard]

Re: high pitch noise- not fan/speaker/lcd.

@ Ole Juul, did you notice he is talking about a laptop? Much of the power supply is outside the computer. I have actually experienced some of the electronic noise you are talking about from desktop PSUs, but never from a laptop.

[Ole Juul]

Re: high pitch noise- not fan/speaker/lcd.

@Telengard: You're probably right. I don't know this model, but many laptops only need an external transformer and even take AC input. There is still a matter of providing different internal voltages. Theoretically the internal DC/DC conversion, which is a "switcher" working in a similar way, could be equally suspect. I do note, however, that you say you've never heard this kind of noise from a laptop. Anyway, it's all speculation.

[some_guy_named_matt]

Re: high pitch noise- not fan/speaker/lcd.

ehhhhh, ok. here's what ive summed up:

- its not hardware, since everything is fine under other OS's [vista, xp, osx] as well as the live cd.

-i couldnt have just noticed it, as im wayyyyy to ocd for that, i cant even sleep if i hear a clock ticking in my room.

- as for the "under load" theory, i dont really believe that anymore, i think the drive noise was just drowning it out.

i dont mind taking my computer apart, ive done it countless times [and no, thats the cause of the noise], i just dont see what thatll accomplish.

[Ole Juul]

Re: high pitch noise- not fan/speaker/lcd.

- its not hardware,

I guess it's software you're hearing then. Cool.

If you still thought it was (possibly) hardware, you could use a stethoscope to localize it. I've used a cardboard tube instead. You've probably seen mechanics take a stick (or long screwdriver) and place it on the side of their ear while probing the source. In this case, because of the high frequency, I think the tube is best. I honestly think that knowing where it's coming from would be useful.

everything is fine under other OS's

Perhaps different video drivers have different scan rates? However, in that case you'd still have to assume that the noise had a physical origin. I'm sorry to push the physical idea, but I don't have any experience with software noises except in as much as it effects the hardware.

[sithlord48]

Re: high pitch noise- not fan/speaker/lcd.

i some times get that but in my case its caused by my cell phone and it only comes from my computers speakers...

in your case its very hard to tell with out having the machine in front of me. but i would take Ole Juul's suggestion and find out where it comes from that should help you narrow it down. once you know the part, i would then check what exactly the system is doing with that part when this noise is happening.

[Ole Juul]

Re: high pitch noise- not fan/speaker/lcd.

Actually, I just did a quick Google and it is a well known problem which Dell has been aware of for quite some time. Apparently some people have it and some don't. Dell can fix it. BTW, it is electrical noise from some component(s) on the MB. The OP can read here: http://forum.notebookreview.com/showthread.php?t=169975 and here: http://forum.notebookreview.com/showthread.php?t=143015 Plus many other places brought up by a search on "dell inspiron 1521 high pitched noise". The OP is possibly right in that in his case it is OS dependent. I say that because the electrical problem is effected by software and Dell even suggested a BIOS upgrade at one point. There are at least some software fixes that work for people. If the machine is still under warranty then Dell will probably deal with it.