Alright, let's get one thing straight: you are not a bad egg-sitter. You have been handed a mystery incubator, a clutch of school eggs, and a hatching date that may as well be a rumor. That is not a failure of your chicken-keeping spirit, that is a fowl setup.
Let's talk about the turner. The egg turner is still in there, and you're worried yanking it out will crash your humidity. Here's the honest truth: those eggs are likely due *today*, around day 20. At that point, the turner is more of a pest than a helper. Chicks need to settle into position for hatching, not get rolled around like laundry. But can you remove it without disaster? Maybe. The real problem is that nobody, not the school, not the internet, and certainly not the unbranded dial, has given you a straight answer. Unplugging the whole incubator to stop the motor is a reasonable guess, but it also means you lose heat and humidity entirely for a few minutes. That is a risk, especially on hatching day.
So what do we actually tell you? Stop guessing at the dial. Stop hunting for a manual that doesn't exist. Your most powerful tool right now is observation. Watch the red dial, if it's a thermostat, you'll see it cycle on and off. Check the temperature with a separate thermometer if you have one. If you don't have one, you're running on faith and hope, which is basically the chicken-keeper's prayer. And here's the practical bit: if the eggs are about to hatch, the turner is likely doing more harm than good. The safest move is to carefully lift the lid, gently remove the turner mechanism by hand (don't yank wires), and seal the incubator back up fast. The humidity will dip for a moment, but if you have a water tray inside, it should recover.
You are not alone in this cluck-tastic scramble. Every chicken person has stared at an unmarked dial and felt a cold sweat. We would tell you this: trust your gut, not the gadget. The eggs don't know they're in a nameless plastic box. They just need steady warmth, decent humidity, and someone to stop messing with them. Turn off the motor if you can, take a breath, and let nature do its thing. If the chicks hatch, you're a hero. If they don't, you learned something, and you definitely learned never to borrow a school incubator again without a hostage situation for the manual.