What is the reason why my amplifier keep blowing fuses If it blows as soon as you put it in and turn the amplifier on (assuming it’s the right kind of fuse), then you probably have blown it up and it will need repair or replacement. If it blows only when you play some music, you may have a short circuit in your wires to your loudspeakers such as a whisker of wire across the terminals, or possibly a shorted drive unit. Furnace control board 3a fuse blows - YouTube Oct 19, 2013not sure why but about 15-20 seconds into the start process the fuse blows. not sure why but about 15-20 seconds into the start process the fuse blows. Skip navigation Sign in. Search.