[Elecraft] K3 split problem

[Bruce McLaughlin]

Well I appear to suddenly have a problem working split on 40 meters CW with
my K3.  It works fine on 20 meters.  Earlier I was chasing CY0X on 20 and
got him using about a 2.5 KHz split.  Later I tried on 40 meters.  I set up
the same split freq on VFO B as I did on 20.  But this time the K3 would not
key.  If I dropped the split and moved up a few KHz to test it keyed OK.
But as soon as I set the split . . . no keying.  It simply did not respond
to the paddle.

Does anyone have any suggestions/ideas?  Thanks.

Bruce-W8FU