hissing from a hub - test-drb@ccmp.vtda.org

24 Nov 2003

Hi
 Pairs of switching power supplies often interreact to
make a sound like hissing. There may not be anything
wrong with it. Still the electrolytic leaking might
be a problem.
Dwight
...
 From: "Curt Vendel"
&lt;curt(a)atarimuseum.com&gt;
No fans....   Hmmmm, see its a design flaw ;-)
Curt
----- Original Message -----
From: "Fred N. van Kempen" &lt;waltje(a)pdp11.nl&gt; 
...
   On Sun, 23 Nov
2003, Curt Vendel wrote:
 > Might be a fan has cracked a bearing, you should try using a wooden pencil
  > or other non-conduct stick-like object and
stop each of the fans  and see if
   the noise
stops, then you'll find the culprit.  OfficeConnect 8's dont have fans.
They're little white boxes
 with an external DC power supply (which, at least for the 240VAC
 European version, sucks.)  I assume it fried one or more of your
 caps, probably the ones that try to flatten the voltage's curve :)
 "3Com - Just Say No!"
 --f