Diagnostic light

Best thing to do is disconnect all the speakers with no input on the amp turn it on and if its still in protection seek help in the repair of said amp at http://performanceteknique.com.. If the protection light goes out then start to put back on each speaker with no volume and the unit off. if you get to a speaker that makes the unit go into protect then leave on that speaker and disconnect all the rest .. If the protect remains then something with that speaker or wiring is bad BUT if after disconnecting the rest of the speakers that you hooked up then theres is still a power issue with your amp

Your amp went into protection mode. It's hard to tell what the problem is without looking at the actual amp. Check to see that the antenna, speakers, etc are all wired correctly. If it is, there might be a short somewhere... Check the troubleshooting section of your manual, it might help.