On Sun, Jul 08, 2007 at 12:41:55AM -0400, Tim Hull wrote: > After reading the ThinkPad wiki link, I've found that the problem has > to do with the C3 and C4 ACPI states. I'm guessing that the 2.6.18 > kernel I was using on Debian Etch just happened to not support full > power management on my MacBook - hence, the problem didn't occur. > > Sorry for all of this - I guess I'll pass this info on to Apple and > see if they may be able to fix this with a firmware update (it occurs > on OS X too).
The most likely source of a noise as you seem to describe is a ceramic capacitor. An alternative is some coil, but that you usually only hear in cases where a high frequency is used inside a voltage convertor (in order to reduce transformator or coil sizes) and I doubt that anything like that is possible in a laptop... I'd have the hear the actual sound to know what it is. 99% chance it's a ceramic capacitor that has to absorb some pulsed current. If you'd replace the capacitor with another one of a different type (same capacity, of course), for example a styroflex one, then the noise would go away. It's very difficult to find out which it is however ;). The only method that I know is by touching each capacitor (ie with pliers) while it is making noise, which will cause the sound to change a little if you have the right one. -- Carlo Wood <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
