The whole system won't turn on

My system is a year and a half old. One day, by mistake I flicked the switch off with my foot. When I tried to turn it back on, it only got on for 2-3 seconds, then the red light faded away. I thought it was the fuse. I've put a new fuse, a 3amp and it blew the fuse once again. But this time the fuse was all black, not like the original, the original was yellow and it looked like it wasn't good anymore. I would like to know if my system is damaged for good, or if I still have a chance to save it. I tought maybe it was the fuse that was not strong enough. I would like to know what fuse this system needs, cause im pretty shure the old one was a 3amp. If it's not the fuse can you help me? thanks! J.P