I think you are referring to "The Rutles" which was a movie parody of the story of the Beatles, not a series. I wasn't born 'till 15 years after it came out so I'm relying on what I heard on vh1 once.
No, I am not referring to The Rutles at all. That was a brilliant TV special that sprung from an SNL sketch (I still own the album, which is actually quite good). I don't recall Al Franken having anything to do with it (though there was alot of cameos.)
His series was called "Lateline" (I think) and was supposed to be a parody of "Nightline." It lasted four episodes, and set a record for the lowest ratings in it's time slot ever.