Still looking for CKT. But I believe the power/inv board is OK. During measuring inverter volts I did get half a display when the inverter started oscillating when I loaded the connection with test meter then switched on. On removing meter lead the board went to standby. I have come to the conclusion it is a ccfl tube fault. My next move is to connect a tube externaly to the board when I get in the mood again, and find out if I am right.