ulocks all the bolts but mortice latch wont open?

hi there may just be the lock barrel that has gone the door needs to be open to replace the the barrel. When the door is open there is a screw in line with the bottom of the barrel on the locking mechanism take out the screw put the key in the lock and turn the lock approx 11.0 clock or 1.0 clock the barrel should push out when it is out turn the key round making sure the throw in the middle is working should turn with the key and should not be able to turn without the key turning. if this is ok then you require a new locking mechanism
bob

b.machnik
January 2010