Weird TiBook Noise

lurk

lurk

Mitä?
Howdy,

I have a non-DVI 667mhz TiBook which is just under a year old now and in the past couple of days it was started to make a weird high pitched whine. At first I thought that it may be a barring going out in the HD or on one of the fans but that is not the case here is the weird part...

If the CPU usage is at 100% the noise goes away. I noticed that there would be a break in the noise when something CPU intensive happened. So I wrote a little program which just spins in a tight loop and when that proggie is running and CPU usage is 100% my TiBook is quiet.

My theory is that there is some crosstalk going on with the some of the audio components (the volume is muted and I still hear the sound) and something related to idling the processor. I saw this before on a PC which would work fine under Windows but would whine under Linux because Windows never actually idled the processor like Linux did.

So here are my questions: Has anyone else noticed this and if so might have it been tied to a recent upgrade to 10.2.3? Is this a hardware failure in that some dampening circuit is dying? Any suggestions for how I can fix things?

Thanks a bunch!

-Eric
 
My PB800 also makes a noise like what you described -- not all the time though. It seems to come on sometimes when graphics card is being worked hard or when the network is going hard. It really doesn't sound like any noise from anything mechanical. I've had the noise since before 10.2.3, but I don't know what's really up either.
 
Thanks for the info. It helps to know that it is something that others have noticed so it is semi-normal. I'll jus invest in some headphones when it get bad.

For the record I found a external firewire hard drive and reinstalled Jag on that to see if the sound was still there in 10.2.0. Lo an behold it went away but then when I went back to the internal drive at 10.2.3 there was no sound either.

So at this point I have decided that the proper fix for this is to reinstall the OS on another drive and then everything will be OK when I go bact to the original drive ;) Ha Ha!

Thanks again,
-Eric

P.S. I never noticed how slow that internal drive was until I grabbed this Firewire disk. I may need to boot off of it more often.
 
TiBooks normally don't make these sounds, even with the latest OS update (that I know of). Posting from a 20th Anniversary Mac with "the buzz" right now... similar symptoms, but years earlier, courtesy of Bose. (Thanks Bose!) In my case, it got worse and worse. If your machine is under AppleCare I'd recommend you have a shop have a cursory look at it (just carry it in and have them bring a tech to the front desk for 30 seconds to listen). Again, if it's a hardware problem (might just be a loose connector) it'll likely get worse and worse over time.
 
Lots of interesting thoughts come to mind on this one but I'm not claiming to have the answer. Capacitors or inductors are typical culprits for noise creation issues like you are describing because they mechanically resonate at certain frequencies. Perhaps there is a filter capacitor in there somewhere which is acting up. I had to return a Linksys router recently because of a bad capacitor which would make this nice squeal after warming up for about a half hour. Do you notice the problem any more or less before or after a warmup period?

If you have access to a microphone you might record the sound and analyze its frequency content on an oscilloscope or perhaps even on your computer. Or you could digitize the sound and mail it to someone who can look at it for you. This may sound dumb but it can be quite illuminating in many respects because it tells you which clock frequency the sound you're hearing is a subharmonic of. This then tells you which part of the computer system is the likely culprit. Plus if the microphone has a nice dynamic range it will "hear" this "sound" at times when you do not. That is to say if the frequency shifts to an above human hearing pitch you'll be able to "see" it even if you don't "hear" it. Does the sound always seem to have the same pitch?

The processor power consumption goes up when you run your instruction-rich program and this extra current draw could help explain the silencing effect also. You might try executing programs of varying instruction loads and see if the noise "tapers" off. I could go on and on about this but I might get booted from the forum for excess verbiage. Good luck.
 
I've also noticed a strange noise with my TiPB 550 since I moved to Jaguar although it's not clear if Jaguar is the cause. This high pitch whine is intermittent and I've noticed that it happens only while surfing the internet and while something is actually being Tx/Rx'd. Strange I know. But so far it's just annoying. For a while I was concerned that a hardware failure would force me into gettin' a new model. Now I hardly notice it.

Cheers
Don
 
Originally posted by Wilsonium
For a while I was concerned that a hardware failure would force me into gettin' a new model. Now I hardly notice it.
Click to expand...

Sorry to hear that! :D ;) Must be a design flaw or something in the PB's then. Sounds like we're all having the same basic thing happen. I wonder if it's true with every current PB out there. Any PB owners out there that are sure they don't have this problem?
 
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