You could check the 115/230 switch. If you are getting power to the unit no fuse or circuit breakers tripped, and you have 8 ohm speakers connected, and a signal in you should get a signal out. Level controls should be up. If all of those things are true, then the amp is broke and needs an electronic technician to repair it.
More than likely the power supply switching transistors have fried. Also check the large caps in the primary side of the power supply. If you don't know what your are doing do not attempt to fix the power supply.. very dangerous voltages involved !!! Send it to Klipsch for repair or purchase a Bash replacement panel http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-750