I just replaced the main power board assy (p/n SGJ-1506A-M2) in this JVC TV. The setup & tuning were routine and all seems well with the exception of the channel up/down buttons. The buttons on the remote and the ones on the TV front panel send the unit to channel 2 and the only way to change the channel is to then enter the channel number on the remote keypad.
The channel up/down buttons were used in the setup process with the new board, so I'm sure they are functioning properly. It seems the logic circuitry is interpreting the signals incorrectly and sending the tuner to channel 2.
I'm hoping someone has some experience with the JVC setup...hopefully I'm missing something simple. In the meantime, I've filed a claim with the part supplier to exchange the board.
Thanks for your response, Dave. Autoprogramming the channels is one of the first tasks accomplished during the setup. It seems to me that the channel up/down commands are being interpretted incorrectly by the control chip which, in turn, commands the tuner incorrectly.
Since my original post, I've returned the board and ordered a replacement. The new unit should arrive on Tuesday.