Have you tried cheeping at it? I had to bring an unhatched egg inside because the mother hen wasn't being motherly anymore and whenever I cheeped at the egg, it cheeped back (even before pipping). I think the sound of you or other chicks cheeping (maybe you could bring the other babies in for a little while) would give encouragement to this chick.
It sounds like you have a handle on the humdity, but just in case, what I did was to place a room humidifier in one of the bathrooms with the door barely cracked and placed the egg in a basket with a light over it for warmth (used my meat thermometer to make sure the light was in the correct position. It took about 6 hours, but the chick did hatch on its own (probably was close to ready when I brought it in).
It sounds like you have a handle on the humdity, but just in case, what I did was to place a room humidifier in one of the bathrooms with the door barely cracked and placed the egg in a basket with a light over it for warmth (used my meat thermometer to make sure the light was in the correct position. It took about 6 hours, but the chick did hatch on its own (probably was close to ready when I brought it in).
