On Sunday, July 18, 2010 09:25:27 am Ralf Mardorf did opine: > On Sun, 2010-07-18 at 11:14 +0200, f...@kokkinizita.net wrote: > > On Sat, Jul 17, 2010 at 10:56:47PM -0400, Gene Heskett wrote: > > > Some lubricant obviously made its way in there, and one would have > > > to assume that the switched current was sufficient to cause a > > > microscopic arcing, which will in time create a smoke film on the > > > internals, which is what you were measuring, and which caused the > > > PSU to think the button was pressed full time. Lubricants are a > > > good idea only on a circuit that can be called a dry circuit, where > > > dry=microamp currents at very low voltages. > > > > Ah, yes, these plastic things are often lubricated. > > > > > Washing it out with acetone was ok, but I would probably have > > > reached for a can of paint thinning alcohol as it is less likely to > > > degrade the plastics. > > > > I know, but the acetone was all I had available... > > > > Ciao, > > Fruit acids or pure alcohols are effective and relatively harmless, but > most effective are products by chemical companies, there are cleaners > with qualities comparable to penetrating oil, but made to fit to > electrical properties. Those cleaners will clean, resp. repair and > protect. > True for the most part, but please do not place the common Freon TF in that category when magnetic media is involved. 15 years ago at the tv station, I got tired of paying for Freon-TF by the gallon, and cleaning the heads on all our VCR's 2-4x daily, and tried cleaning one with paint thinner alcohol from ACE Hardware. I didn't have to clean it again for a week! So I switched cleaning agents on the spot. And it turned out that Freon-TF was also much harder on the elastomer parts like pinch rollers. I cut the time spent cleaning heads and rollers by 90%. Roller replacements went way down too.
-- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Humor in the Court: Q. Doctor, did you say he was shot in the woods? A. No, I said he was shot in the lumbar region. _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev