Using this lever puzzle, how would I make my piston door turn OFF when the puzzle is correct? [MC1.14.2]
All you have to do is remove the signal inverter that uses a redstone torch. Here it is in the video tutorial (at 5:30):
All you have to do is replace the torch with redstone, like this:
As you can see, the doors are now open, even though the visible redstone is powered off. You can do everything else as it is in the video.