Date: Fri, 12 Sep 1997 01:12:31 -0600 (MDT) From: Doug Russell <drussell@saturn-tech.com> To: Pius Fischer <pius@ienet.com> Cc: freebsd-hardware@FreeBSD.ORG, terryl@ienet.com, robert@ienet.com Subject: Re: wdunwedge failed Message-ID: <Pine.BSF.3.95.970912010750.7856B-100000@hobbes.saturn-tech.com> In-Reply-To: <199709120321.UAA25833@iago.ienet.com>
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On Thu, 11 Sep 1997, Pius Fischer wrote: > Sorry, for the very late reply ... Hehe.... Happens to the best of us. :) > On Thu, 21 Aug 1997, drussell@saturn-tech.com wrote: > >On Thu, 21 Aug 1997, Mike Smith wrote: > > It may not be the problem, but I would take a multimeter and check out the > > +12 volt supply while the machine is in this failed state. The hard drive > > most likely uses the 12 volt for spindle motor, etc., and most VGA cards > > use the +12 and -12 supplies for the RAMDAC. If the 12 volt line is > > really funky (might need a scope to see if it is fluctuating, poorly > > filtered due to a dead filter capacitor or something, etc.), the power > > supply is the suspect. > > > > Method B, of course, is to swap in a known good supply, and see if the > > problem happens again. :) > > > > You'd be surprised how many strange problems are caused by a flakey power > > supply. Don't ever buy one of those cheapo $30 mini-tower (or whatever) > > case deals. The power supply in a $30 case probably isn't too wonderful. > > Getting better built cases is an added bonus, too. :) > > Yes, the power supply was indeed the problem! The voltmeter reading > across the bad machine's power supply was a very unsteady 13 - 13.5 > volts (if I remember correctly). On a good machine standing next to > it, the voltmeter gave a rock solid 12.3 volt reading. We then got a > slightly fancier chassis with a new power supply and we haven't seen > this wdunwedge/flickering monitor problem again. People probably don't suspect the P/S as often as they should. Testing it out or swapping in another one for strange crashing problems, etc. is often a good idea. There is no substitute for good hardware, folks, and that includes things like like the power supply. Later...... <Doug>
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