Don, thank for the excellent guidance. I'll begin the debug process. By the way, I have eliminated spurious contact between the encoder board and control board, as I debugged that some weeks ago: https://www.mail-archive.com/elecraft@mailman.qth.net/msg219585.html. There is now room between the boards such that the plastic packing material you mention moves freely about without friction. This spurious contact possibility was one of the first things I checked today when the "c" indicator would not light.
On Sun, Jun 10, 2018 at 4:43 PM, Don Wilhelm <donw...@embarqmail.com> wrote: > Mark, > > Analyzing the switch matrix is an iterative process > The first thing to do is to determine which wrong responses are being > sent, and for that you must refer to the schematic. In your case of the > REV button and the STP 60 display, the hold of the REV button is bringing > up the PF1 display. > Check the TAP function of the same button (AGC) to see if it brings up the > RIT announciator (I think it will). > If so, it means that the D1 and D2 lines are somehow being activated at > the same time. > Your first check would be to see if there is continuity between pins 12 > and 13 of U2. Also check for continuity to ground for both of those > lines. If you find U2 pins 12 and 13 shorted together, look for the reason > - a solder splash making a bridge or a bit of wire lead stuck between the > pins, look top and bottom of the board. > That is how the process goes - as I indicated, it is not 'nice'. > > Hopefully those two buttons are the only ones involved. > At worst, it means removing the pushbuttons and replacing them with new. > If it comes to that, clip the leads on the switch side close to the switch > body and remove the leads one at a time, then troubleshoot the board. > > 73, > Don W3FPR > > > On 6/10/2018 7:15 PM, Mark Petrovic wrote: > >> Thanks, Don. >> >> Would you mind outlining the approach for analyzing the front panel >> switch matrix? >> >> >> >> > -- Mark ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
