Flight deck won't reset
 

I just replaced the batteries in two Flight Decks. Mine works fine and is still displaying the ride data that was on it when I pulled the old battery. But my wife's is no longer working (or rather the FD that was formerly my wife's and is now mine). :) When I installed the new battery, her FD appeared to go into reset - the little Km/h is flashing on the right side of the screen - but I can't get the computer to function. If I press and release the AC (all clear) button the display briefly flashes data in all the registers (so the battery is connecting fine). After about 2 seconds it goes to the Km/h screen which the manual says is the initial data entry screen. At that point I can get no response pressing the B or A buttons off the harness or the shifter buttons when in the harness. It was working fine previously.

Any suggestions?