The short answer to this is, turn it off when you’re not using it. Here’s the long answer, if you’re interested.
After trying to watch the Watchmen movie recently, my Sony DG-720 receiver kept saying “Protect” and shutting off every time the assassin knocks the Comedian’s door hinge off early in the movie. After some research, it seems that this can be due to a short in the wiring, but the reason for my receiver doing this was apparently that it was overheated.
I unplugged the receiver for several minutes, then did a hard reset by holding the power button. This worked, but I suspect that all I really needed to do was turn it off then walk away for a while. I’d been leaving the receiver on all the time, but maybe this isn’t a good idea as it does get a bit hot.
Naturally (for me at least), that solution wasn’t good enough. I decided to enhance the cooling capability of my Target entertainment center hutch thing by drilling some holes above where the receiver sits. I used a 1 1/2 inch hole saw and cut the pattern as seen in the photos and drawing below. These holes were then sanded with a file and sprayed with blue spray-paint. I wiped it off as best I could on the uncut part.
My hope is that the warm air above the receiver will go out of the holes, thus “sucking” air in from the front where the receiver sits. After watching the last hour or so of Watchmen (the next day after keeping it off), the back of the receiver was warm, but the space above the drilled shelf was hot too. Some hot air seems to be going through the holes, which should cause the air flow situation (illustrated below) that I wanted. How much air flow is the question.
Results: After leaving the receiver on for an hour or so, roughly 20 minutes of which it was being actively used, I put in the Watchmen movie again. It went through the first fight scene turned up fairly high with no problem. I wouldn’t call this a scientific test; the receiver was probably on much longer before, but for what it’s worth, the receiver did not overheat. Did it make a difference? Maybe a little, but it looks cool and definitely won’t hurt.