Disable tuner?

I have a bad tuner in my Tivo Premier XL. Tuner 0 is gone, but tuner 1 still has a good signal (37db). My tivo doesn't know this, however, and tries to record on tuner 0. Is there a way to manually disable tuner 0 so that my Tivo won't use it at all, and will warn me if I have two recordings at the same time?

Thanks!