About 4 or 5 months months ago one of our HR20-100 receivers failed, so DirecTV just mailed out a replacement. Now the replacement receiver (an HR21) is making awful sounds. Either a fan is going out or the hard drive is about to fail. The unit is clearly audible across the room. So much that I unplug it at night. Is DirecTV going to put up a fuss about replacing this unit or do the refurbs commonly fail? The date on the unit is 12/07 making it 4.5 years old, so probably not unlikely the drive is failing or something else. Just looking for others experience with replacement units. I don't want DirecTV to think I am an abusive customer to their equipment. I just install it and forget it.