On Roamio OTA TV screen will go black and no sound at random times for a few seconds or up to several minutes before resuming having skipped the programing (live or recorded) for the duration of the outage. Happens on live viewing or recorded playback after being on for an unpredictable amount of time. Outage will repeat randomly if TiVo is left on with no intervention. If TiVo is unplugged for a few hours it operates normally after startup but experiences same behavior after an unpredictable amount of time. I replaced the fan thinking it may have not have been cooling adequately but that did not help. I am considering replacing the hard drive but not sure if a faulty drive would cause the erratic behavior. Suggestions?