Wait, what? You "... took power away from them ..."? As in turned the power source * OFF *? I thought they needed power 1 unit? Sorry, let me rephrase what i said. The mortars seem to fire once the power is taken away from them. I used a switch connected to a generator and the mortar. The mortar is supplied with power and once that power is taken away, it fires. Seems like it should be the other way around and fire when it's powered but i was just saying something with the hopes that it might fix something. Yes - so it looks like you have found a "Bug" ... and yes I tried your post, as I thought I understood it and NO it would not fire as I thought would happen. Haha, i thought that was just how the mortars work. So, I'm guessing that they fire once you give them power? That could also make sense because those advanced logic gate were acting strange for me but i made a workaround. I've never even touched the new DLC until i read this thread so i don't have too much knowledge on them and i'm still playing with it. Also could you give me the steps to replicate your "challenge"? I'll give another shot and see if i can replicate it.