[Elecraft] Help please - Smoking K2 - no s meter or power controll etc

[john petters G3YPZ]

Greetings
I have just built the KIO2 interface. My K2 has been fine until I came to
modify my control board to add the I/O. I gor info 090. This led me up the
garden path. I un modified the board and had a whole lot of weird effects.
Finally I reset the K2 to its default settings and it worked. I then
remodified the board and tested it and it still worked. I inserted the I'O
board, switched on and smoke appeared I disconnected the I/O switched on
again and I now have no s meter, now TX power control(although the display
says it it changing the power) no ssb signal although I have full carrier
power on all bands. The S meter Hi and lo calibrations do not work, neither
do the grph indications. I get no power indication on the bar display on
transmit.  U6 is version 2.01.
I do not know where the smoke came from. It seemed to be from thr RF board
but I can see no sgns of burnt components.
Any ideas greatly received.
Extra frustrated due to having just completed (successfully I think )the 2M
XV.
73
John Petters
Amateur Radio Station G3YPZ
www.traditional-jazz.com