Noticed while watching and recording MNF last night (HR20-700 still running 17e, updated to 18a overnight) that I couldn't switch over to the Braves game during commercials -- when I tried, I got the conflict screen informing me that the only operational tuner was already in use. I did a system info check and both sat tuners and OTA tuner showed full acquisition; then I did a signal meter check and noticed that Tuner 2 was at 0% across the board. I thought it might be a bad BBC so I switched the Sat input cables -- no fix. Went ahead and did a RBR (because I know that is what D* tech service would tell me to do first anyway) and that cured the problem, both tuners back up and functional. Why could cause one tuner to fail completely but be cured by RBR? Is this an early warning sign that my HR20-700 is at risk to fail, or at least lose a tuner? Would love your thoughts, thanks.