Bought this not long ago used, and worked great. Now all of a sudden won't turn on (no standby button, nothing). I am using the correct lead/fuse for the system, and have checked fuse and all working Ok. What could possibly be the problem? I've opened it up and no signs of damage/wires are all connected.
The most common failure in self powered subwoofers is the amplifier itself. Contact the manufacturer. If it's still under the two year warranty they should take care of it. If not many companies offer reasonably priced replacement amps.