How do you know it is the logic board in the 7000? Check the ribbon cables from the panel to the main board before you decide it is bad. As a matter of fact check the signals to the board from the rest of the radio as well.
I doubt that the logic circuit will be easy to find, anyway.
I had problems with these ribbi=on cables before as the want to crack and lose connections.
Also if id is the connections to the board have you tried controlling the radio from a program like Ham Radio Deluxe?
If the radio turns on from the panel then there is some communications between the logic and the cpu in the front panel.