Why doesn't the clicking noise stop?

I have a Hi-Fi that has worked flawlessly over the years. Last night as I was listening to music through the aux cord, the sound suddenly went out. As I pressed the volume buttons to see if something had turned down the volume I noticed that the touch buttons weren’t working correctly. Then, this weird clicking noise gradually started coming out the speakers and it wouldn’t stop (even after I had unplugged the aux cord from the unit). I have to unplug the power cord from the speaker in order for the sound to stop. Any time I plug the power cord back on the clicking noise begins as soon as the aux cord comes into contact with anything and I have to unplug the power again. Is there a way to fix this? :(