if everything works with the z gecko switched to the y wires. sounds like the old y gecko is dead . Might pull it apart see if you can see anything burnt up. any copper on the board melted ect. Some times that is easy to fix yourself. if not m sure gecko will not have a problem testing it for you. Only thing will be the wait

but with the sale prices now might be a good idea to have a backup gecko around anyway. might also try the basic smell test

does it have a nice burnt smell? :P