How to copy playlists from one mac to another.

I have decades worth of playlists I've crated over multiple mac book pros.

My latest macbook pro died the video card issue but I still have a VERY slow 2008 one that works and has iTunes and all my playlists.

when i try and migrate it to my mac mini I get all the playlists and music but all the playlists are empty.

looking at the xml code it seems that my directory structures are the same since the HD are named the same and both have the same user id name.

what am I missing?

John