S.S.
In my opinion, he is overtired and when that happens they get so wound up they can't sleep. Do they have to be in the same room? If they do, I would put the youngest to bed first so he's asleep when you put the older one in there. Yes, TVs are not such a good idea in their rooms. I would let the little guy sleep as long as he wants for his nap and then put him to bed by 7:30 at the latest. Sometimes when they start catching up on their sleep they can take long, long naps and still turn around and go back to sleep in just a couple of hours. He sounds chronically overtired and that makes it very hard to go to sleep. If it were me, as a last resort, and if I couldn't make it work in his room, and after letting him sleep as long as he wanted for his nap, ( I had to do this with my first one) I would put him to bed in my bed by 7:30 and no later, even if I had to lay down with him, telling him this is just for a few nights, and then very quietly transfer him to his bed after the other one was asleep and the house was quiet. When he starts catching up on sleep everything will seem better. Good luck!