In Minas Morgul, when Gondor breaks the gate there is a blast sound as usual, but the gate itself does not open. Mordor cannot open the gate with the lever, it says that the 'gate is broken, repair it first' - it cannot be repaired either.
Edit: it can be repaired, but when broken a second time the same thing happened.
Edit: it can be repaired, but when broken a second time the same thing happened.
