hissing from a hub

From: Ian Primus <ian_primus_at_yahoo.com>
Date: Sun Nov 23 16:33:20 2003

On Sunday, November 23, 2003, at 05:04 PM, Fred N. van Kempen wrote:

> 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 :)
>
I've actually seen this problem before, on a 3Com hub. They used some
of those defective capacitors (remember that problem with faulty caps a
few years ago?), so they are prone to fail. The hissing is probably
just the electrolyte boiling and escaping as the caps heat up. I've
seen a hub where the caps finally exploded. Just replace the caps, and
it should work fine. Either that, or buy another hub. These things are
so cheap now, that it may actually be cheaper to replace the whole hub
than to buy a handful of capacitors. (Of course, that's not the point,
now is it? Things shouldn't be just thrown out if they don't work, they
should be repaired. It's much more fun that way, anyway.)

Ian Primus
ian_primus_at_yahoo.com
Received on Sun Nov 23 2003 - 16:33:20 GMT