From: cd999666@notformail.com   
      
   On Sun, 15 Sep 2024 22:46:18 -0700, John Robertson wrote:   
      
   > On 2024-09-15 9:44 a.m., Nick Hayward wrote:   
   >> Hi all,   
   >>   
   >> I have a switch which isn't making electrical contact. It consists of   
   >> two leaf springs. Dead simple. They're springy enough to push against   
   >> each other alright. And I've cleaned them with ethanol (didn't work)   
   >> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant   
   >> (didn't work either). I am at a complete loss here. Has anyone come   
   >> across something like this? I can confidently say I never have!   
   >   
   > Have you verified that the meter leads are making good electrical   
   > contact to the switch blades? Oxidation can fool any of us! Touch one   
   > probe to the switch blade, and touch the other probe further down the   
   > blade - repeat on the other side, only then check for electrical contact   
   > closure once you are certain you have good probe connections.   
   >   
   > John :-#)#   
      
   Acting on the advice of someone very much more experienced with this   
   attenuator  than I am, it's the case that the offending material was   
   silicon oxide. Something to do with contact sparking and silicon grease   
   that they used in the early versions of this device. The only remedy is   
   fine abrasive paper. I used 1500 grit in then end; very lightly just a few   
   strokes. it's fine again now - and before anyone says anything, there was   
   no gold plating on these contacts to rub off!   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)