Redstone wire powered via redstone comparators (or any block that can provide an output of <15 signal strength, such as weighted pressure plates or trapped chests) that are themselves powered with a signal strength <15 have an odd effect where blocks that should be powered via a strongly powered block under the redstone wire with a signal strength of 1 are not powered if redstone wire is placed on top of them (the redstone wire on top of them has a signal strength of 0, so it looks like the blocks think they should be unpowered, and ignore the strongly-powered block adjacent to them).
Steps to reproduce
Construct the build shown in the screenshot "Without redstone dust.png". Notice how the redstone lamps at the end are powered, as they should be.
Place redstone wire on top of the last lamps. Notice how, like in "With redstone dust.png", the redstone lamp turns off, because it thinks it should be unpowered. This happens only in the case where the comparator output level is <15; when its output level is 15, the lamp remains on.
Original description
In the attachment, you can see that even though all redstone lines have the same signal strength, only the one that isn't powered by a comparator turns on the lamp on its right. If you remove the unpowered redstone on top of those lamps, they all become lit.
[media]Linked issues
is duplicated by 1
Attachments
Comments 13
Confirmed in 0.15.0. (Tested in Windows 10.) Very strange indeed...
EDIT: I think this behavior may be related to MCPE-14204.
Confirmed for 1.2.0.18.
This behaviour also seems to affect trapped chests; the redstone output is inconsistent when placed over redstone lamps:
[media]
MCPE-22667 was closed as a duplicate of this issue. However, 22667 describes an additional fact that I don't believe is described in this ticket: This screenshot shows two versions of a circuit. In both of them, the redstone dust on the green block is at power level 1, but in one of them the redstone lamp is on and in the other it's off. The only difference is that in the one where the lamp is on the comparator is outputting power level 15, whereas in the other one the power level out of the comparator is at level 14. So placing redstone dust on the lamp only turns the lamp off if the dust is being powered by a comparator whose output level is less than 15.
Can no longer reproduce this issue with comparators in Windows 10 1.2.9.1. However, the issue with a trapped chest continues to happen.
It turns out the issue still happens with comparators, too, with the right length of redstone wire and power level into the comparator.
[media]
Confirmed in 0.14.1. Very strange...