Last weekend I left my receiver on in a rush to go somewhere. Come Wednesday I then noticed a hum? Oh, crap. Left it on in the cabinet enclosed except for maybe a crack. Not good enough. It was hot inside the cabinet and now when I turn it on there is a very audible hum coming from the speakers. Think I fried something. Can't believe I did this. Luckily I paid $50 for it and I'm in the process of buying another for $35. A damn shame it's cheaper to throw it out than to fix it because of a mistake on my part. It's been a solid unit. Arggg!