Radio stops working

[Lucas03ES]

My car has an aftermarket pioneer deck, and all 6 speakers are pioneer/lightning audio. I was driving down the freeway the other day, and then suddenly everything cuts out, and all sound was lost from the speakers. The deck still appeared to be functioning perfectly fine. So a couple days later, I was swapping my battery out (Relocated to trunk), and when I got in the car, the radio magically worked. It worked for another couple hours until it just cut out again. Could the deck be bad, or could it be something else? Thanks!

 

[turbowop]

Flaky ground connection possibly.

 

[Lucas03ES]

I connected the ground to one of the four screws going into the metal piece directly behind the deck. Is that a bad spot? Where have you guys put yours?