Wish you luck. Maybe a board repair tech can help? I have service manual on this unit if they need it.
Dont even bother calling Graphtec about the board... Not the same caliber as the ole' FC3100 but I have a 24" CE5000 that I can offer you a good price on. May be about the same price as a replacement mainboard if you can find one, unless you can get the old one refurbished.