[Elecraft] K2 transmit power instability on 20 & 12 meters

[David C Dawson]

My K2 (05386) has developed a problem affecting the 20 meter and 12
meter bands only. When I key up, the power fluctuates wildly. On the 20
meter band rx seems normal, on 12 there is a chorus of birdies.
My assumption is that a common component was cold-soldered or has
failed.
I note that in the relay table, K13,K14 & K15 are energized together
only on those two bands.
Before I start the troubleshooting, I'd like to know what components
could be the culprits?
Or any other (helpful) suggestions. (I have an rf probe still)
Thanks.
-- 
David Dawson

The Ranger isn't gonna like it, Yogi.