TiVo HD, had an external drive that I think failed as I can hear the hard drive grinding and the TiVo wouldn't boot up. I removed the external drive, now I am stuck in a loop where it tells me my external drive is missing, I follow the instructions to reboot to remove it, then I am back at the same external drive missing screen. I can't get past it. It's like it needs the external drive to be readable in order for it to divorce it from the system and successfully reboot. What are my options?