Audio Systems: amp has power but no sound, rca cables, rca output

Question
I installed 3 different amps, 1000 watt amp, a 600 watt, and a 300 watt amp in my berretta, they all light up but no sound comes out.  I've used 3 different sets of rca cables, with no results.  I tried different set speakers and still no results.  The speakers connected to the 100 watt brand new pyle plus stereo work but the speakers connected to the amp do not. Do you think something is wrong with the stereo rca output?

Answer
Robert,

 you have done some good troubleshooting trying different amps .. if all 3 never showed signs of sound but had power .. its more than likly your head unit... before you invest in a new one see if a friend has one you can wire up and test or if you have an old one laying around that has RCA pre outs use it to test .... but i would almost lay down cash that its the head unit giving you the problem .. hope this helps you out if you need anything else let me know

thanks