underscoregoeshere

I have a 2003 Sequoia and the homelink just recently stopped working.
No lights or anything when I press any of the buttons. The map lights
work, so it isn't the fuse. Of course, it isn't covered by the extended
warranty, so my question is this: Is the home link from other toyotas a
box that plugs into the external controls, or is it all built in there
together? The gist of my question, is can I fix it myself by finding a
part somewhere, or do I have to let the dealership do it? Thanks for
any help.

Doug