Went to turn on my airco units, and one didn't fire up. Tracked it down to the FX-1 board pretty quickly. Spoke to Roger in tech support, and he confirmed it. The replacement was shipped and received very promptly. Worked perfectly. I must say that the new board is a much better layout, and has improved circuitry. CAUTION!! If you are replacing an original board which has a large rectangular transformer, you will note that it is supported with 2 threaded standoffs. DEFINITELY remove these before installing the new rev, board, as it could short out the board traces to case. I have reported this to Micro Air engineering group, and they confirm this is an issue which they will document with new boards they supply.