anyone know anything about electronics?

well my amp stopped working so i took it apart and then i saw the fuse was blown anyway i left the cover off and then i hooked it up to see if it would work again (after changing the fuse) andthe fuse didnt blow, but the power light didnt come on and it started smoking out of this black thing (transistor i think) anyway, can i just replace the transistor or should i bring it to someone to fix it. i got the amp for free so i dont really want to spend cash on it, can anyone help