My Wii's broken and i can't sync my remotes?

I don't know if its the remote's or the wii but after i took two of my remotes to my friends house and synced them with her wii i couldn't sinc them again on mine. One remote works that i didn't take but only that one and my wii fit doesn't work and i didn't take that round there. But i did manage to sync them all by going on the house button then on remote settings and pressing them all at the same time but i tried to fix my wii fit and now only one remote works... Whats wrong with it?