HU makes a funny sound

Well my HU makes a funny sound like a buzz when playing music right b4 it stops playing sometime it will come back and play the cd/fm radio but sometimes it wont.I have checked all the wires all fine.It will play but then it it make a buzz/pop sounds and the HU will display ATT on it.What could be wrong.My system is Panasonic Cq-C7301u 2x Precision Power Dcx 1000.1 2x PA Mofo 15.I also have a 200amp alt the big 3 done and a yeloow top batt pls help.

Scoot