[Elecraft] K3 Stops Transmitting (solved)

[Dennis]

A couple of weeks ago I posted that my K3 suddenly stopped transmitting 
during ARRL CW.
The PTT would enable, it was not in TEST mode, the CW monitor would 
sound, but no output.
Pushing the TUNE button would result in "0 watts" showing on the 
display.  The problem
persisted after I power cycled the radio, plugged/unplugged the DC 
source, tried various
control changes, and a soft "drop" test.  Through all of this, the Rx 
worked just fine.  Nothing
restored the radio transmitting ability.  So, I swapped it out and 
continued the contest.

When I got home, I hooked the radio up and it transmitted just fine.  
Something happened that
stopped the radio from transmitting, but now it worked fine.  So I 
posted my experiences here
and asked for suggestions.

A number suggested the DC power supply cable.  My experiences at the 
site suggested that wasn't
the culprit.  A number suggested that I had somehow put the radio into 
"TEST" mode, but I was
sure I had not.  I even toggled into and out of "TEST" mode several 
times, but that didn't solve
the problem.  Several suggested that a voltage had been applied to the 
Inhibit pin of the ACC15
connector, but there was nothing plugged into the ACC15 socket.  Two 
suggestions seemed
most plausible: that one of the coax cables from the new synthesizer to 
the other boards was
intermittent, or that the Sub Rx plugs was intermittent.

Once I had a place to look, I opened the radio and did the following:
1. Took a pair of long nose pliers and GENTLY rotated and firmly seated 
each coaxial cable
connector connecting the synthesizer board to the rest of the radio.  
All seemed to be secure
and in tight, but they were all rotated just a little.
2. Checked the seating of the Sub Rx into its connectors.  The back 
connector was not fully
seated- I'd say it was about 80% seated, but there is a little play in 
the connector.  It is now
fully seated.

Since then, I've operated the radio about 30 hours in contesting. The no 
transmit problem
has not come back.  Did I fix it?  The problem had never happened 
before, I don't have a
clear problem that was solved, but it has made it 30 hours now without a 
problem.  At least
for now, I feel the problem has been solved.

Dennis W1UE