Yes, from talking to someone who works on the assembly line in Dell here in Limerick, they seem to have totally different manufacturing standards, tolerances, etc, for the high-end laptops and for the cheap ones.

On Mon, 2006-11-13 at 17:04 +0100, Carlo Capocasa wrote: No, there's no possible software fix for this hardware problem. Lee

On Mon, Nov 13, 2006 at 06:14:35PM +0100, Pieter Palmers wrote: I'd be surprised if this would turn out to be singing capacitor. Every switched-mode voltage regulator needs a an inductor, and these are much more likely to 'sing'. Probably you have a badly designed or specified regulator that fails when the load is below a minimum value (a classic problem with SM regulators). To test this, load the power supply e.g. via the USB connectors (a simple USB powered keyboard light could be enough). If you can locate the component, and it turns out to be an inductor, applying a bit of epoxy glue on the winding will probably silence it. -- FA Lascia la spina, cogli la rosa.

Carlo Capocasa wrote: An inductor is a coil of wire wound (several turns) around some kind of core. If it's an encapsulated type it may be harder to identify. http://en.wikipedia.org/wiki/Inductor Ok - that's likely the supply regulators. You're not expecting additional hum. An inductor smooths out current flow in circuits by storing energy magnetically. Because there's a magnetic field (coil of wire and electric current), there's also a force exerted on the coil (think electric motor) which _can_ cause the coil to physically move in sympathy with the current. The physical movement of the coil acts like a loudspeaker - but this isn't a tune you can dance to. Do you have a stethoscope? Unload the machine and get that noise back. Now listen. Can you identify the component? R

On Thu, Nov 16, 2006 at 08:40:58AM +0000, Rob Fell wrote: They can take many forms, down to a simple ferrite bead on a wire. That would work if the stethoscope's pickup is small. Or you could use a 'microphone probe', a small mic with an acoustic tube fitted. Another practical trick is this. You need a small wooden stick - it should be light, hard, and of course non-conducting. A wooden match or toothpick would do. Use it to *lightly* touch the component you suspect. This should change the sound, and you may also feel it with your fingers. -- FA Lascia la spina, cogli la rosa.

The high load thing worked; I noticed that the singing disappeared when I started programs, moved some windows, etc. So I posted "Singing Capacitor Fix wanted" and discribed I wanted a load generator. Karsten supplied me with this: --QUOTE-- A simple load generator with low scheduling priority: echo 'for ((;1;)); do i=0; done;'|nice -n 19 sh -- -- This works like daisy. I included it in QJackCtl and it works like a charm. No performance penalty, and the noise is completely gone. Of course there might be heat issues to deal with, but they can be solved seperately. Now I need to test with my Roland Edirol card, this was using the Alsa driver. Will keep you guys posted. Carlo

James McDermott wrote: Well, my experience with Dells was desktops and laptops aimed at business. The employer I mentioned earlier, where switching to Dell hardware tripled our hardware troublecall rate, was primarily using desktops, not laptops. So I'm guessing that the hardware was not coming from the cheap end of the Dell spectrum. -- David gnome(a)hawaii.rr.com authenticity, honesty, community