I'm guessing its the one you rushed, just a little?? Hopefully you know I'm not trying to be mean, but that's why we cautioned you to be patient. He'll be fine, he just needs a little more time.
Do you happen to have, or be able to get, some Nutridrench? I'd give him a straight drop of two of it, followed by some clean water to wash it down.
Also, make sure your brooder isn't too warm for him. Sometimes when they lay around, if they get too warm, it takes them longer to get up and about. Ya know, we all just want to lay around when its hot outside! lol
You can even hold him and try to stimulate him a little. Is the other one bothering him, or cuddling up to him?