I bought a Roamio OTA in September 2017, and it ran quiet until February 2018, when it started to make a loud buzzing sound after I'd unplugged it for a hard reset. From everything I read online it appeared to be the fan. In trying to figure out how to open it to either lube the fan or replace it, I unplugged the Roamio and then plugged it back it about about 2-3 times, with the higher pitched and noisier howling on start up seeming to confirm it was the fan. Until last time it would settle back into its regular noise after startup. However, last Saturday once it went through startup, it became quiet again. I can still hear the fan running when I put my ear close to the Roamio, and its temp is staying around 33 C, so I'm guessing the fan is running right and doing its job. So, what has happened for it to first be noisy then go quiet again? Needless to say, I'm not touching a thing, it's wonderful to have a quiet living room again.