> 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. This is an EXCELLENT lead. Thanks Fons. Can you give me a hint on how to identify an inductor? My notebook case is open right now and the whine comes from a place out of or near the CPU. Also, the whine comes when I start Jack at low latencies; I don't quite understand what the purpose of loading the power supply would be; I've hooked up my Palm Zire or a USB microphone (which sounded like crap, but did load the power supply) and experienced no additional hum whatsoever. Carlo
