Thanks guys for answering my previous question. I have some follow up on it. I did mentioned that I have changed my enderman farm design since then and have new problem with it.

So here is the problem, I have a row of extended pistons but they are not powered as you can see from the unpowered redstone behind the pistons.They supposed to be retracted so that the enderman could spawn. It seems that the pistons are not updated. they only retract when I put a block above the row of pistons.

Is there any ways to solve it without having to climb up onto the spawning spawning and updating pistons every time? Hopefully this question is not too localized.

  • This is a known issue with this type of design, where unloading the chunks while the pistons are active will leave the pistons active after reloading the chunk. Either that or you have unintentionally created a BUD.
    – MBraedley
    May 4, 2013 at 11:30

1 Answer 1


Your design is capable of causing the pistons to act as BUDs because the redstone underneath the pistons are powering the blocks underneath them, which are in the correct position to indirectly power the pistons in the level below them.

I do not see any way to fix your design to eliminate the problem while still keeping the same overall layout unless you go back to using tripwires.

  • Oh man, I think I see what you mean. To paraphrase what you had said for clarification: So as each layer consist of same piston pusher setup, the redstone that is beside the pressure plates on the next layer is affecting the pistons on the layer below and thus the whole setup creates BUD switches unintendedly... This sucks for me as I have already changed my design a fews times and each time it takes quite some time. I guess I have no choice but to go back to the tripwire design. May 4, 2013 at 13:58
  • Yes that is what will be happening. May 4, 2013 at 14:12
  • 2
    @StevenCunningham actually there is a nice one if you have a good amount of slimeballs here May 4, 2013 at 19:51

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