Thanks to Harry, WE1X, for letting me know of a similar button problem he had. It is most likely my problem is not caused by the components I suspected, but rather by the failure of the switch inside the encoder for Speed/Mic.
I was thinking only of the rubber-covered buttons, which cannot result in a ground out. However the four encoders containing push switches can fail by putting a ground out to a scan line. There were a few failures on early encoders, and Elecraft now uses encoders from a different source. I sent my front panel board back for repair. 73, Paul K5ESW > Seven of my front panel buttons do not function on K3 #757. I also used the > Switch Test to see that they give no scan codes. All other buttons work OK. > > Looking at the the schematic for the "Front Panel - Switches" I see these > seven > buttons are all connected to the SCANADC0 line into U3. I took off the front > panel and put an ohmmeter from ground to the SCANADC0 line, and it gives a few > ohms. The other lines (SCANADC1-7) show as open. > > I looks like either U3, C30, or R27 is bad. Does anyone see any other > possibilities? > > I don't relish replacing U3 since it is a 16-pin IC. Maybe some Chip-Quik or > tiny cutters to snip the leads would ease the job. > > 73, > Paul > K5ESW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
