Broken Stereos

Old stereo equipment sucks. Funny story about that... When we moved to our new house, we bought surround systems for both upstairs and downstairs. Then, a couple months ago, I had a birthday party. The day of the party, I was cleaning up the basement, when I went to try the stereo system to make sure everything was ready for later that night. I hit the power button, and...nothing. No sound came out at all. All the speakers, or at least the subwoofer that powered them all, were dead. Needless to say, my dad was pretty pissed, so he grounded me for a month. Needless to say, I was pretty pissed at being grounded for a month, so I hid his keys. I hadn't done anything to make it break! Then, a couple weeks ago, there was an incident. Now, generally we leave our upstairs stereo system powered on whether we're in there or not. This includes at night. That night, we did as usual, and then went to bed. According to my dad, that night, something went terribly wrong, causing the stereo to emit varying, violently loud signals at around 3 in the morning. I was a little skeptical, as I hadn't even awakened. He was skeptical that I hadn't even awoken also. So, he grounded me. But still, I was skeptical. Then, one night we were watching Big Brother when the stereo went on another rampage of hatred-filled screams. Now, we had the stereo up quite loud as we were watching, but when these noises sounded, the pain in my ears reverberated for weeks. Luckily, I got the stereo turned off reasonably fast. And when I turned it back on, WALLAH! It worked just fine. But the worst of all came only last night. We were sound asleep, and the surround sound was on. Around 6:27AM, the noise came. This time, it was a mildly-high pitched whine. But INCREDIBLY loud! It hurt my ears 3 rooms away. But, I was lazy so I just bared it until my dad turned it off.