OK, here are the ways I tried to kill my eggs:
Humidity went to 70% after they were first set. I refilled the water tray when I first set them and didn't notice it had overflowed into the other trays, so after eight hours I pulled everybody out and dried up the spill.
On day ten, I unplugged the turner to plug in my candler (the cord was too short to reach the bator from my other electrical outlet) and forgot to plug it back in until a day and a half later.
Somewhere around day 15 (?) I let it run out of water and the humidity hit 20%. Couldn't have been longer than a day.
On day 18, I removed the turner, filled the second water tray and set the eggs on this super cool, nifty neat-O, anti-roll, home made Styrofoam egg holder. Closed the lid and watched the humidity DROP to 40%. The egg holder was sealing off the water trays. I shuffled the eggs around to get my Styrofoam pieces out, took the Styrofoam out to the shop and ran them through the table saw to cut dado grooves in the bottom to allow air flow. I reset the eggs and watched the humidity rise to 50%. And stay there. I opened the bator back up, shuffled the eggs again and set them on the wire rack. I did manage to install some permanent plumbing into the humidity tray, that worked great for filling and draining the water.
And . . . . . . . . . TA DA, we got chicks. 28 of the litter critters. First pip on the evening of day 19 ( Feb. 9th.)and the last hatch the night of the 21st day ( Feb. 11th.).
We set 37. 3 were clear on day 10 and removed. 5 quitters around day 15 (?) and one fully developed but never pipped. I opened up the eggs that didn't hatch this afternoon.