why would a fully dev. chick die; the membrane was hard for me to get

[Yogalady]

checked an egg, membrane was HARD to get through but chick was fully developed, looked like it could have walked had it's eyes been open - there was still some yolk or other fluid but not much -

Would a chick alive, be moving when we candled?
Or, as soon as we opened would a live but dying chick move somewhat? This was not alive at all...

My friend said (she has chickens) that even with bobwhite quail wait another week past 'due" hatch as they can run quite late.... we are waiting we still have a few days but this seems fruitless.

I just want to figure out what we are doing wrong!
42 eggs, humidity between 45-70, temp 100-101, hover little giant still air.

The ONLY thing I could tell was that we had a power outage but I guess the temp may have dropped even lower than I thought? I thought it only dropped to 82

 

[Akane]

That humidity is all over. At 42% it's likely the membrane would get too dry and the chicks would be unable to hatch. At 70% that's borderline to drowning point in my bator. Different setups vary. I incubate at 40-50% aiming for 43-45% if possible and hatch at 60-70% trying to get as close to 65% as I can.

 

[Yogalady]

I was doing the lower humidity and then raising it as people said I should - so it wasn't like one day 45 the next 70 and such - it was more in the 50 range then I upped it with the sponges...

I am so completely confused!

 

[Scraps]

I do exactly as Akane said. The first 18 days around 45% and the last 3 days at 65%.

I've hatched over 100 chicks the last few months and have only lost 2 or 3 of them. On the last 3 days I have kept both vent plugs in because I didn't read the directions that came with my bator. On my last hatch a few days ago, I left the plugs out like it said to. The humidity was hard to keep steady and I only had 13 out of 20 hatch. The 7 that didn't were fully developed and most likely drowned. I think the key is to keep trying until you find whats right for you and what works. Don't give up!!