I am having a hard time with my amp (see sig). It plays fine untill it goes into test mode. I have checked my ground wire a million times. I even tried a different bolt. all paint chiped off, straight to the chasis. I am sure its not the ground. It is also not overheating. Sometimes it shuts off after 10 minutes, othertimes 30 min. I am starting to think perhaps the power source is not stable enough ? but that is hard to believe because thats my only amp. Also, I shipped my amp to maxsonics and they shipped a new one back to me, and it does the same thing. Any thoughts ?