Thanks for the input. No, I haven't had the rig open in more than a year. It hasn't moved from its current operating position in weeks. No rattling loose screws.
There is a strong possibility that the input was over-voltaged due to a short in a separate piece of equipment that was powered from the same 12VDC buss. The other item has both 12VDC and 24 VDC inputs, and it's possible that the 12V line got "bumped up" to 24V. That would be consistent with Dale's description of the issue. I will pull the cover off later this afternoon or tomorrow morning and check the diode, and look for any obvious places where the smoke has been let out of a component. Thanks for the good feedback, guys. Lew N6LEW On Oct 19, 2012, at 7:11 AM, "Jim Miller" <jimmil...@stl-online.net> wrote: > First thought: Is there any chance you may have dropped something (screw, > etc.) into it at any time and now it has moved to create the short? Remove > covers and turn it every which way and shake it and even bump it firmly with > you palm over a table or non-carpeted floor and listen carefully. > > Now the questions: Have you had the covers off and now it doesn't work? > Were you installing or removing options? Disconnect or remove them to > isolate. > What have you done "recently" other than operate it? > Have you moved it? > Were you poking around inside so a connector came loose and is now touching > ground? > > Isolation of the problem: I had a phono jack on the back that lost > conductivity with ground and blew up my amp by allowing power into the amp > without pulling the transmit line active. I chased the problem by using the > minor resistance differences to get close to the problem area and then found > 2 of the phono jacks were soldered but no connection to ground. Wire bridge > to another ground point solved my problem. Try to remove/unplug/otherwise > disconnect components to remove the short. You may even find that screw you > lost during construction. Hi hi > > Good luck, Having a K3 not working really SUCKS. > > 73, de Jim KG0KP > > -----Original Message----- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Lewis Phelps > Sent: Friday, October 19, 2012 1:50 AM > To: Elecraft@mailman.qth.net List > Subject: [Elecraft] [K3] short circuit at power terminals > > Yikes! My reliable K3-10 has developed a short circuit across the power > input terminals. Well, to be exact, not quite a dead short. It measures 0.6 > ohms across the PowerPole connectors. It most certainly does blow fuses on > the input line. > > Any suggestions for trouble shooting? And also for a possible cause of the > problem? > > Lew N6LEW > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
