Having drive comm error problem wiring looks good an only grounded on one end.Everything pointing to replacing the U8/U9 Drive Chips on the 1036 board.Has anyone done this an if so what should I look out for.I have a spare board in the car station 1025JN With the same number that's on the U8/U9 chips,are they interchangeable?

U8/U9 chips are interchangeable if the # on the chip is the same. There is no memory or program on them, they act only as "switches" so to speak, gated logic.

Thanks Wolf