[Elecraft] K3 ERR TXG

[Rowland]

I have installed my Xmas present  the KPA3 into K3 36
All seems to be OK apart from an error message, ERR TXG on the 30m band 
only.
Other bands seem OK and acting as should.
When trying to transmit into a dummy load 50Ohm  I get no power out and 
hear a 200Hz or so whine coming from the rig.

The manual says that usually indicates a problem with band-pass foilter 
alignment or one of the low pass filters. See Service manual.

Anyone any ideas please.
I guess elecraft tech help not available today.

Thanks
Rowland
G4APO