I have a rivera knucklehead k-100 head on a marshall jcm800 1960 cab.... I was jamming tonight and heard a pop.... I looked over and the amp shut off. I then smelled some electrical smoke, and checked the main fuse and then a fuse that was right next to it.... both were completly fine. I waited and tried to turn it own again and nothing...... It won't come on.... anyone got any ideas? any input would be greatly appreciated!!!!!