[Elecraft] K3 12 err

[John]

Today I was tx ssb when I noticed the power was lower than usual and there was a 12 ERR message on screen.
I turned the rig off and checked the power supply...13.75 volts, tightened the connections and turned the rig on again.
It would only turn up to 8 watts indicated on the screen.  I turned the power up and on the way up I got the 12 ERR 
message again without tx.
I turned it off and on again and was able to turn the power up to 100 watts but when I tried to tx, the ERR message 
came up again and 8 watts indicated.
Power amp fried?
John.