[Elecraft] K3 - ERR 12V

[Ed K1EP]

All of a sudden this morning, I started getting an error message on 
my K3, ERR 12V.  Then it scrolled Check Circuit Breaker, which I 
assume was the PA circuit breaker.  The radio would not transmit 
until power cycled and the power level was reset to below 12W.  I am 
not convinced that it is a thermal issue, although it could be.  I 
monitored the PA temp and it doesn't have a direct 
correlation.  Temps are in the high 30's to low 40's.  I removed the 
top cover and inspected the circuit breaker.  There seems to be 
significant IR drop (10s of mv) across it even when not transmitting, 
so I am wondering if maybe the circuit breaker is failing.  Has 
anyone seen anything like this before?