[Elecraft] K1 Problem

[Phil Wheeler]

I'm getting my K1 set up for a camping trip tomorrow.

Problem is that it works fine on 30, 20 and 15.  But on 40 Tune gives me 
0.1 Watt and r=9.9 with lots of relay chatter (this into a resonant 
antenna or a G5RV); seems to hear fine on 40.  K2/100 + KAT100 loads it 
with no action at all.

What should I look for that would only affect 40?  I've aready done the 
trimmer replacement, so a bad trimmer is not real likely.  Since I have 
other things to prep for the trip, I'm hoping for something quick and 
easy .. but not expecting it :-/

TIA es 73,

Phil