[MC-127] Piston extended and retracted at the same time

After placing pistons on top of one another, top piston will remain extended. However, it will still work, but it will prevent an item to be placed in front. It is like a phantom extension that takes the place of the block in front of it.

Linked issues

is duplicated by 40

MC-254 By pushing the sugar cane with a piston, it is defective Resolved

MC-2316 Minecraft Piston/Repeater/Sugarcane, Possible Bug? Resolved

MC-2896 Pistons Malfunction Badly Resolved

MC-3418 Pistons creates piston heads when they break sugar cane Resolved

MC-3686 Piston doesnt rectract though it has no signal, if a neighboor piston farms a pumpkin. Resolved

35 more links

relates to 4

MC-108 Droppers, Dispensers and Pistons activate when blocks are providing power diagonally or two blocks above Resolved

MC-6486 Variable redstone strength causing strange update behavior Resolved

MC-8198 Piston pushing piston bugs / piston duplicating piston Resolved

MC-59564 Retracting piston has two heads Resolved

Attachments

NetherTrap3.7z

Step by step description on how to create a completly stuck and unusable piston, part 1.jpg

Step by step description on how to create a stuck and completely unusable piston, part 2.jpg

Step by step description on how to create a stuck and completely unusable piston (not that this specific variant of the stuck pistons bug is new in 13w01b!), part 4.jpg

Step by step description on how to create a stuck and completly unusable piston, part 3.jpg

Comments 48

Erik Broes 2012-10-25T02:59:14Z

Are you able to recreate this? it seems only 1 piston out of the manylots is suffering from the problem. A contained testcase would be wonderful.

Matthew Salsamendi 2012-10-25T23:56:06Z

This is a repeatable bug. However, redstone power needs to be from one redstone repeater positioned between both pistons (powers the two pistons at the same time) this will break the pistons on top.

Mark scape 2012-10-26T00:01:19Z

I've had this problem also. I was able to get the pistons to glitch by powering it like so: http://i.imgur.com/kuzsN.png However, it only happened to me while the top piston was pushing sugar cane. If no sugar cane was in the way of the top piston, it would retract normally.

Thue 2012-10-26T00:04:00Z

How to reproduce the bug is described here: http://www.youtube.com/watch?v=A3cidpdOElA . I just verified that it is still in 1.4.2.

Mark scape 2012-10-26T00:04:54Z

Here's a screenshot of the way (I think) Matthew did it: http://puu.sh/1iJUO You can see the top piston is both retracted and extended. It also only happened to me while it was pushing sugarcane.

38 more comments

Chalmes (Jon) 2012-11-22T19:47:13Z

Adding comment to suggest looking at MC-3686 for easily reproducable version.

marco de ocampo 2012-11-30T11:30:16Z

i have the same problem in 1.4.5 and that hapens on cakes doors shugarcane i dont know any more 🙂

Raja Branco 2012-12-26T21:15:31Z

This is also a directional bug, only happens when the piston is facing North/South (F:2/F:0).
To happen, the piston must push something.

Sims112 2012-12-27T12:42:21Z

It can also happen in East / West direction - it's about how you power it: http://i.imgur.com/Jh6gF.png

Raja Branco 2012-12-27T12:46:11Z

oh, ok, my bad then, I tried with pistons facing those directions but didn't happen anything, I think I didn't powered them the same way then. My bad.

Sims112 2012-12-29T18:23:46Z

Yeah at first, I also only got the bug in N/S direction because I powered it different

Ville Selkämaa 2013-01-01T19:17:55Z

Confirmed in 1.4.7

Flasheek 2013-01-04T15:34:14Z

Confirmed in 13w01a-b, this time caused by new Redstone Blocks. Description and a couple of ways to reproduce here: MC-6005

Flasheek 2013-01-04T15:57:17Z

Or I'll just attach a couple of images

Sims112 2013-01-05T02:20:25Z

Another screenshot of 30w01b - exactly this setup did bug the piston out everytime it pushed the sugarcane

Austin Quick 2013-01-07T04:35:40Z

Another instance of this bug in 13w01b. Everything needed to reproduce is visible. Piston's glitch when F=0 & F=2.

*Note: The top block must be powered via lever.

Note: the redstone dust below is required for the bug, and must be un-powered at the same instant the pistons are powered.

asdf 2013-01-07T04:54:43Z

I have found another way to produce this bug - as a byproduct of another bug I seem to have found in issue MC-6486.

Rolf Campbell 2013-01-08T22:45:52Z

Every attempt I make to create a Zombie-Pigman farm using pistons is crippled by this bug. The pistons involved seem to randomly get stuck in this quasi-extended state. My pistons that are stuck in this state are powered by a redstone-repeater behind it (at the same elevation). I don't think this bug is limited to oddly powered pistons.

Rolf Campbell 2013-01-09T03:13:19Z

Attached a world that shows this happening to normally powered pistons.

Rolf Campbell 2013-01-09T22:37:51Z

In creative mode, you can break the extended arm of the piston and it (temporarily) returns to normal operation.

Charlie McFadden 2013-01-12T04:23:46Z

This bug is very annoying! When I tried making a semi-automatic Sugar cane farm, if would work fine before the sugar cane grew, but when the sugar cane grew to its normal 3 block "ready to harvest" state, I stepped on the pressure plate and all but 2 of the top pistons didn't retract...its like when the pistons broke sugar cane, it cloned the piston arm when it retracted.

asdf 2013-01-12T05:44:32Z

@Charlie McFadden
Worse than the piston cloning a block glitch, it's the dreaded block cloning a piston glitch!

GCSX 2013-01-12T16:47:37Z

Added 3 screenshot of a mechanism reproducing this behavior.

The two pistons receive inverted and synchronized power, making their arms to stagger.

The first is the system once built, the second is then system swithed on and the last is the system switched off again.

Notice the bug on the right piston.

megascience 2013-01-20T07:31:32Z

My screenshots (Hoppers, Comparators, and Pistons) is another way to reliably reproduce this problem. Whenever the working piston is placed next to the one that can break, it will. How it is set up: Two Hoppers feed into each other. A single Minecart with Hopper is placed inside, constantly transferring between the two. The Comparators turn on and off in one-tick pulses into the Pistons.

Sims112 2013-01-23T12:23:04Z

Woohoo I can't wait until my sugarcanefarm works again

Raja Branco 2013-01-24T17:39:37Z

it's resolved! 😃

asdf 2013-01-24T18:47:11Z

Correction: it's SUPPOSEDLY resolved. TO THE TESTING RANGE!

Raja Branco 2013-01-24T22:38:03Z

exactly xD

Raphael 2013-02-07T15:46:46Z

Well, it says here that this has been fixed, but i actually just encountered this bug in 13w05b. It looks exactly the same like the ones in the screenshots and i also wanted to upload the screenshots i made, but somehow this java popup upload window doesnt work for me; when i press the "paste" button, nothing happens, although the screenshot is in the clipboard.

asdf 2013-02-07T16:00:15Z

Press the plus button next to the attachments header and upload using that instead.

Raphael 2013-02-07T16:36:05Z

@Christian
Thx that worked. And it added the comments that were supposed for the screenshots in the commentsection. :/

asdf 2013-02-11T04:49:51Z

It has been fixed in the latest snapshot. Not the version that has already been released. If it were fixed in the version that was already released, it would be 1.4.8 instead of 1.4.7.

Fabio Vaz 2013-02-11T04:58:26Z

Two pistons, one on top of the other, both pushing sugar cane when turned on. The top piston will remain extended when turned off (see attached picture). Is this bug report still active or should I create a new one ?

Raphael 2013-02-11T07:01:48Z

nvm. It wasnt fixed in the snapshot were it was supposed to be fixed, but in the newest one it is fixed.

Dlawso the Really Lucky Rabbit 2014-06-28T23:49:08Z

Its back in 14w26. (MC-59564 / MC-59812)

kumasasa 2014-07-02T06:15:14Z

Reopened.

Sam Bone 2014-07-03T16:31:04Z

Confirmed for 14w27b.

J. P. Coder 2014-07-13T17:11:39Z

i have it in 14w28b (broke iron farm!)

BoxFigs 2014-10-10T22:03:39Z

Does this issue cover both the bug where pistons are stuck in this state (which I cannot reproduce in 1.8) and the visual glitch that always happens when a piston retracts?

atomizer 2014-10-11T13:17:30Z

This is about the stuck state, not the animation. Unable to reproduce in 1.8

BoxFigs 2014-10-11T19:21:10Z

Well, some moderators have been marking reports about the visual glitch (such as MC-65314) as duplicates of this one, so I was confused.

atomizer 2014-10-11T19:38:22Z

Oh, you are right. I have no idea then.

BoxFigs 2014-10-12T18:42:07Z

Nevermind, I found the right report for the visual glitch: MC-59564

I guess some of the moderators closed some reports as duplicates of this issue instead of that one.

kumasasa 2014-10-12T20:01:47Z

Relinked the wrong duplicates to MC-59564 and re-resolved this ticket.

Sam Bone 2015-08-06T23:22:23Z

This is back in 15w32b!!! Oh no!

Sam Bone 2015-08-06T23:27:10Z

Oops the one on the right appears it is stuck but it is pulsing, but the one in the middle is glitched.

kumasasa 2015-08-07T05:27:27Z

@@unknown: MC-59564

Brady Coles 2019-08-13T05:41:53Z

This bug appears to be back in 1.14.4. I've experienced it several times, but only in one particular contraption, it was not experienced prior to at least 1.14 (ie. it was not present in the 1.14 snapshots). Pistons are unpowered and both extended and not extended. Powering and unpowering the piston resolves the issue (but it leads to slimestone contraptions breaking). It is not guaranteed to occur, and normally doesn't, but I have found these pistons in this configuration at least 5 times in the last several weeks.

Note, there are 8 pistons in this contraption, firing at 4 different times, with several seconds delay between some of the activations, and yet when the pistons become double headed usually most or all the pistons are double headed. I believe the contraption is in spawn chunks (possibly lazy), and is triggered by a daylight sensor, so it might be related to lazy chunks.

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I have not tried to reproduce the bug in other contraptions or configurations.