Thanks to all who help. I installed two Xtant 404m and used a 100 amp fuse on 4 guage power wire to distribution block, 8 guage off that to each amp. The ground is on a distribution block, grounded to one point for both amps. I have led lights on both amps and each was working last night but the rca cable touched and now no sound from one amp. I used a volt meter and it registered between 6-7 volts at the power and remote turn on of the amp thats not working. Still have led lights (red) on both amps. Wondering if i blew the amp or is the ground point messed up. Any word on these older xtant amp too. If I need to replace it whats comparable to quality and sound these days. Im running both amps at 200wx2 on 4 ohms.