[Elecraft] K3: A new wrinkle on no KPA problem?

[jmalloy]

Hi folks, thanks to those who offered advice on the failure of my KPA3 
to actually amplify anything.  A new wrinkle has turned up as of this 
afternoon when I resumed testing on it: the KPA3 works every now and 
then very *briefly* and after it does I get the ERR 12V message on my 
display which points towards a the circuit breaker.  I have checked the 
circuit breaker out of circuit and it seems fine.  Anyone have a hint at 
what I should look at/for?

Many thanks!

73,

Joe, W2RBA