Thanks to all that actualy replied to the question in the post
thanks mancigames, for the link you posted
but i still don't accept moisture being the reason why blowing makes the carts work. It can't be the reason since all the contacts are extreamly clean (in the systems and on the carts) - the connectors inside the sytems are new or in great condition -- its always the same carts
it could be wear on the edge connector traces where the moisture could be a factor- but i have carts that look like they have extreme wear that work every time
i gues ill just have to accept its unexplainable to me - beasue logic tells me that moisture shouldnt play a part in the conduction - since there is more than enough super clean metal contacting each other
thanks all again