If the lighter is sparking, then check to see if it is sparking towards the butane release valve. If it is not sparking towards the butane release valve, this is why the lighter doesn't work. The spark is not igniting the butane. Again, using a small screwdriver readjust the electrode. Be careful and adjust the electrode wire towards the middle where the butane release valve is.
Little adjustments are all that is needed.
After each adjustment, try lighting the lighter. If you break the electrode, buy a new lighter, this one is broken. If you don't, then put a new flint in and your lighter will probably work. If you do have a flint and your lighter is still not sparking, then try turning the flint around to the side that has not been used. Another possible reason for a flint lighter to stop working is that the flint may not be connecting with the flint wheel.