Subject: Re: dead fans in ds5k/125
To: Joachim Buss , <port-pmax@netbsd.org>
From: Chris <talon16m@hotmail.com>
List: port-pmax
Date: 06/20/2000 20:23:38
on 6/20/00 5:53 AM, Joachim Buss at TK97EL12@technis.syh.fi wrote something
like:

<snip>

> Of course I can rewire 12V from a hdd connector to the fans but
> I'm just wondering if somebody else have had the same problem
> and fixed the fans' connector ...

    While I've never opened a switching reg. before, I imagine that the fans
have their own voltage regulator, they may also me variable speed depending
on CPU temperature. (My 5000/240 has a t/3/misc/overtemp in the test list)
It may just be that a 12V regulator or a triac went bad. Assuming one of the
fans isn't shorted out and/or wired in series of course. Barring those
symptoms, the fans probably don't need full wave rectified DC, so I bet they
tap off the 12v AC line before it gets bridged down and filtered. Perhaps a
rectifier/diode bit the dust; not likely, but possible. Then there's the
most often not-checked cold solder joints. Just some thoughts.


    Chris