Somewhere between the RCA inputs and the speaker outputs, there is something wrong. The amp gets power, doesn't go into protect, and the RCAs and head unit are good. Where should I start checking? Here are pics of the same amp, just not mine.
http://ampguts.realmofexcursion.com/Hifonics_Zeus_ZX6400/
http://ampguts.realmofexcursion.com/Hifonics_Zeus_ZX6400/