[linux-audio-user] Re: The famous "Jack Hum" (Can't record and desparate)

[Fons Adriaensen]

On Thu, Nov 16, 2006 at 08:40:58AM +0000, Rob Fell wrote:

> >Can you give me a hint on how to identify an inductor? My notebook case
> 
> 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.

They can take many forms, down to a simple ferrite bead on a wire.
 
> Do you have a stethoscope? Unload the machine and get that noise back. 
> Now listen.  Can you identify the component?

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.