patio door?

is it french doors or a patio door.
if a patio get a pencil mark the frame where the gearing goes into the keeps and check they are in the correct position.
if not remove one at a time then try locking the door.
do this till either there are no more on the outer frame or it works.
then replace checking that it still locks when replacing each one.
even if this means moving them to a new position.

midas
October 2010