[Elecraft] K3 suddenly dies

[Richard Fjeld]

Yes, that will reset the crowbar SCR.  The DC must return to zero for it to reset.

I would recommend a brass brush for cleaning connections if possible, and maybe a .22 caliber brush (used for cleaning guns) for getting into some places.  I'd not use anything too abrasive.  (I never touch gold plated contacts.)  I'd test first.

I'm hoping you will find your correct voltage on the end of the power cord.  But, if you are in a salt air environment, I have seen what that can cause. Let us know.

  ----- Original Message ----- 
  From: Gary, W7TEA 
  To: elecraft at mailman.qth.net 
  Sent: Friday, October 04, 2013 3:52 PM
  Subject: Re: [Elecraft] K3 suddenly dies


  Thank you Dick.  I will be returning to that QTH with another power supply and cable,  deoxit and sandpaper to clean connections.  I did turn the offending Astron supply off and on at the switch but didn't unplug it.  Would that have been enough to reset the crowbar circuit?  

  Gary W7TEA



  On Oct 4, 2013, at 1:23 PM, Richard Fjeld [via Elecraft] <ml-node+s365791n7579576h21 at n2.nabble.com> wrote:

  > This may be premature, but if you don't find trouble, it could have been that the 'crowbar' circuit on the regulator board may have operated to protect your radio from high voltage, in which case doing a power cycle on the PS will have reset it. 
  > 
  > We had a thread relating to this one year ago. 
  > 
  > I have seen the crowbar circuit operated in several power supplies without a fuse blowing.  The PS just cooked until reset.  Not much of a problem if the PS is attended, but some of the power supplies were un-attended and got quite hot. 
  > 
  > I have looked into the possibility of modifying the circuit to blow a fuse when this happens, but it would be a thread of it's own.   
  > 
  > Dick, n0ce 
  > 
  > 
  >