Alright so I have been bored this summer so decided to take apart my electronics such as my Xbox and AV receiver. I installed a nice 12vdc computer fan on the side of my Xbox so I moved onto my AV receiver and then ran into some problems. My current set up consists of: 2x - 12vdc computer fans 1x - regular light switch 1x - 18vdc transformer (from old computer speakers or something) I understand that I will be running 9 volts to each fan which is not a problem and I have it wired all correctly, *I think*, but for some reason both of the 18vdc transformers I used overheated and stop working whenever I had them switched off. The fans ran fine for 10 or 15 minutes but once I turned the switch off with the plug still in the wall it overheated and would not turn the fans back on. I am guessing the problem is closing the circuit and backing up the electricity into the transformer causing it to overheat and fail but that is honestly my best guess. Please let me know if you need any other information. Thanks, jheiges P.S. If anyone could help me rewire my circuit to run off extra power in the AV receiver so that powering the receiver off would turn the fans off that would be amazing! I wired my Xbox to the disk drive extra 12volts and would love to do the same with my receiver.