It *could* still be the HD, I guess. That was just my experience. Although, usually when the HD goes, there are other symptoms. It's *probably* not the HD.
But if the HD does go, yes, you would have to connect the cable box directly to the TV directly. Just as if you didn't have the TiVo (cause if the HD goes, you kinda don't
at least, until you fix it). If the HD ever does go, the folks here can get you up and running again.