----- Original Message -----
From: "Vintage Computer Festival" <vcf_at_siconic.com>
To: "Classic Computers Mailing List" <cctalk_at_classiccmp.org>
Sent: Sunday, November 23, 2003 4:35 PM
Subject: OT: hissing from a hub
>
> I've got this 3Com OfficeConnect Dual Speed Hub 8 that is putting out this
> obnoxious hissing noise. It's loud enough to be annoying and add
> significantly to the white noise in my office. It sounds like the air is
> slowly being let out of a tire...forever. I've opened it up and found a
> capacitor with some brownish crusty stuff caked on the top of it. It also
> was bulged ever so slight at the top, as was another one right by it.
> Both are within proximity of the power connector. I didn't see any
> blackened spots on the enclosure indiciating that either had let out any
> magic smoke.
>
> So the question is, what is the most likely cause for this hissing? I've
> had a device before where the capacitor was causing the hiss (or at least
> I was pretty sure). There doesn't seem to be anything else in there that
> would cause the hissing (a bunch of ICs, a couple couls, a couple power
> transistors, etc.)
>
> Any help appreciated.
>
> --
>
> Sellam Ismail Vintage Computer
Festival
> --------------------------------------------------------------------------
----
> International Man of Intrigue and Danger
http://www.vintage.org
>
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>
>
Capacitors will boil over when hit with higher voltage then their
specification. Maybe your just hearing the electrolyte boiling? Try running
the thing without the cover and you might see a small vapor trail. Did you
by chance use the wrong power adapter for the hub causing a voltage problem?
Received on Sun Nov 23 2003 - 15:42:22 GMT