Factorio Forums

I have 3 chambers in line, the middle one doesn't output anything 06-33.png[/attachment] I have replaced the chamber watched it working but the inserter never moved it just output spoilage. I don't understand why.

I would check everything related to that biochamber - input inserter, output inserters, output chest, biochamber itself; whether they operate as expected, are not clogged by unexpected items, etc.

If everything looks fine and the middle biochamber is getting fewer mash than other biochambers, the issue might be timing - mash is coming on the belt in sparse groups, inserter for the first biochamber takes what its handsize allows, leaving only one mash of the group.
Second inserter takes that one mash, waits for a little while for next ones, then gives up and inserts into biochamber. As it is swinging there and back, another group of mash comes along the belt, missing it altogether and feeding the third biochamber.