Re: [nslu2-general] Re: NSLU is making high frequency noise
- Most likely noting is really wrong. What you are hearing is almost the
windings or the core halves contracting as the current through the
part cycles. This is probably just due to the fact that the glue that
holds the core halves together wasn't applied too thoroughly or it was
wound somewhat loosely, though there is a slim chance it's indicating
hight current. The coil is probably electrically fine, though it might
fail early if the windings are moving and scrubbing their insulation off.
From what you described and hints from the picture this is probably part
of a small on board switching power supply that is used to generate
another supply voltage.
You might be able to quiet it down by running some really thn lacquer
into it, but you're just as likely to dissolve insulation and short it
out. This will probably kill the switch transistor and other parts
I wonder if others are missing C31, C14 and C17? There are a lot of
unstuffed parts on this board. I guess they are used for option
selection or alternate parts. Now I need to look at some of mine.
Nicely done pic BTW.
> Well.. thanks for the suggestions. I guess, i have found the source of
> the whine.
> I'm pretty sure it's one of the coils, like Hendrik said. When i touch
> the L2 coil with a screwdriver, the sound goes absolutely insane..
> So now i wonder, is the coil bad, or could something be causing this
> L2 is on the left center (marked 220 on top)
> What are these things for?
Southlake, TX 76092 (Near DFW Airport)
- Hi again,
This coil is probably a part of a DC/DC step down converter, to generate a
lower voltage than 5V.
It could be a mechanical fault on the coil, that makes it vibrate when the
DC/DC converter is running chopped DC current through it.
Maybe try add a small droplet of glue if you find any part of the coil that
is responsible for the noise.
Is your NSLU working normally except for the noise?
Från: firstname.lastname@example.org [mailto:email@example.com]
Skickat: den 5 november 2009 22:54
Ämne: [nslu2-general] Re: NSLU is making high frequency noise
Well.. thanks for the suggestions. I guess, i have found the source of the
I'm pretty sure it's one of the coils, like Hendrik said. When i touch the
L2 coil with a screwdriver, the sound goes absolutely insane..
So now i wonder, is the coil bad, or could something be causing this
L2 is on the left center (marked 220 on top)
What are these things for?
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