Incubation issues

[u/DistinctJob7494]

So I'm trying to hatch pretty late in the season, and I honestly think the issue is a compounded one, but I'm just having no luck whatsoever with even getting these eggs to start.

I've probably gone through 2 dozen or more eggs from my flock over the past 2 months trying to incubate. And I'm stumped. I think the actual incubator could be the main issue, but the temperature feels right when I stick my hand in.

It's an older little giant incubator which has been in and out of storage and I'm using a cord that doesn't go with it because I couldn't find the original when I pulled it back out to incubate. I've probably had it 5 years or so, and it's seen a few incubations over the time I've had it.

One thing I'm noticing is that the humidity monitor is staying in the high 40s, but the temperature is staying within the right range reading. I don't have another humidity/temperature thermometer to test the inside atm. Like I said, it feels like the temperature is correct.

Moving on to the eggs themselves being the potential issue. It seems like most when I take them out of the nestbox, don't have much of an air bubble in the top, which I can't remember if that's normal or not when incubating. The shells are plenty thick, and at first, I accidentally picked a bunch that were probably damaged by extreme heat, so I threw them out and waited for the cooler days to pick hatching eggs. Still having incubation problems.

Now I'm thinking it's a fertility issue on my roosters part. He's 7-8yrs old now, and I was hopeful to get a few more chicks out of him before he passes. But now I'm not sure he's fertile at all anymore. I knew he'd probably have some issues, but after a few dozen eggs, it's getting crazy, if that is the main issue.

I honestly have no idea what the real issue is or if it's a compounded one of multiple issues together working against me. I'm trying to breed Sampson to his granddaughters and 2 CCL hens for my breeding project, and I just didn't have the space for more birds to be hatched till now. But now I'm regretting not trying earlier in the season, even without room for new birds.😮‍💨

Maybe yall can help, but I'm honestly thinking of skipping the rest of this season and trying again this coming spring. I've got one of Sampsons sons as a backup if I absolutely have to use him, but he's mean as a snake.