> True. :-( You might be able to temporarily shield that inductor, > but that's a shot in the dark.
The only thing I can think of is to remove the input diode for the switcher (to power it down) and feed it 3.3 from an LDO through the test point, and see if that makes a difference. I do *not* expect I'll be able to remove any of the SMT parts therein; I'd need to get it on the hotplate to do that, and the through-hole parts preclude that. Not tonight, though :-P > > PCB traces? > > Yes, they can actually resonate. I know you've been working with > desktop computers for a very long time (I used DJGPP in ~1992)...have > you ever noticed a "squealing" sound coming from a machine when it's > busy, changing with processor activity? Sometimes that's the power > supply, but it's usually traces on the motherboard. The only "cpu busy" sounds I've ever heard are when there's an AM radio around the CPU. And I know my hearing is good; I can hear when the monitors are on (15.75KHz). And I can hear this sound too, even across the room, and my wife says she doesn't hear it at all unless she puts her ear next to it. _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
