[Elecraft] K3 issue

[Dick Frey]

My k3 keeps losing its mind. One day it won't transmit SSB - I can whistle
up 100W but speech gives 5W of avg and ~15W peak.
On another day it says "KAT500 not turned ON". I have a KPA500 but no
KAT500.
My fix for both these has been to do a factory reset and reload my last
saved configuration -- not something you want to do in the middle of a
contest.
Any ideas on what might be causing its lapse into insanity?
-- 
Dick - K4XU