Take the amp out of the speaker box. Disconnect the two speaker wires after labeling them and disconnect the multi-pin connector. Ship the amp wrapped in bubble to:
EBC Electronics LLC
908-458-6072
126 S 14th ave, Manville, NJ, 08835
The repair cost should be $150 to $300.
I have had EBC repair five of them. They come back sounding brand new.
Good luck,
J