I have noticed this in the last few months. It is ALWAYS either humming, grinding etc....If I am watching tv/movie you can't hear it, but if the tv is off you can positively hear it. At first I thought it was the tv, my first BIG flat screen, no its the 625. This would be my 3rd in years..the other two had hardrive crashes. I'd like to take care of this BEFORE that happens. Its NOT hot, its very open/air wise. I realize they do downloading, updates etc..but really??? 24/7. I have a 311 in another room, I realize its not a dvr but I have had it for what 10 years and it's drop dead quiet. Should I contact dish? thanks