Hatch rate analysis - what went wrong?

*Disclaimer: Some images/videos may be gross.
 
On day 24 (April 14 at 9 pm) I've pulled the plug and did the dreaded clean up of the incubator.  It was not fun -- nasty and smelled like rotten fish.

I tossed a dozen eggs that did not pip (chick start to punch a hole) and 6 eggs that had some pips (small to medium cracks) but did not progress any further.  There was one chick still inside the incubator that hatched last night but her navel did not heal and was still swollen so she did not survive.  Three died within 48 hours after hatching.  I helped one of them hatch – definitely not recommended.  And one chick that looked so healthy and fluffy died for no apparent reason after 24 hours.

Egg# 155. I tried to help this one but didn’t work.

What went wrong?  Cheap incubator or quality of my breeding flock?  I’d like to think that it could be due to the  3-hour power failure on day 20 (a very crucial day) which explains why  I had a high rate of deaths in the “full-term and failed to pip” and “pipped and failed to hatch” categories.

21 out of 48 eggs set hatched.  Out of these 48 eggs, 44 were fertile.  So the hatch rate among fertile eggs is a lousy 48%.  If I include all the eggs in the incubator, the hatch rate is even lousier at 44%.  But hey, this is my first time.

Below is the summary of the hatch rate:

Line		Number
A	Eggs set	48
B	Not fertile	4
C	Dead at first candling (days 10-12)	1
D	Dead at second candling (day 17)	1
E	Full-term, failed to pip	12
F	Pipped, failed to hatch	6
G	Died within 36 hours after hatching	3
H	Total lost = B+C+D+E+F+G	27
I	Total hatched = A-H	21
J	Percent hatched = I x 100/A	43.8
K	Percent of fertiles hatched = I x 100 / (A-B)	47.7

I investigated and cracked open most of those “full-term, failed to pip” and “pipped, failed to hatch”.  But before that, I want to share egg id 152 (green egg) who died immediately after I removed from the incubator.  Here’s the video:

And below are a few videos of what I found inside those dead-in-shell chicks.  Caution, some pictures may be a bit gross to see/watch.

Egg id# 198

Egg id# 164

Despite this, I have a second batch of eggs in the incubator already.  And 4 of are duck eggs.  I hope this works because ducks have a longer term before they hatch.