What size ground and power wires?
Where is ground connected?
I keep asking as I do think you have a wiring issue and I want to make sure whatever amp you replace it with will last you.
4 gauge knukoncepts wiring grounded to the trunk frame sanded and bolted. It worked fine for 2 weeks before it went in protect and never came back outc
I also recommend either the CAB 1600 or the RP2000
I am running the RP2000 and am very happy with it's performance.
I run it at 1 ohm, my ride to work is 30 min each way, I play it full tilt and it handles it with getting just slightly warm.