Well my problem is very simple. I have a KDC 135 (Kenwood). I was taking the car out for a spin and it was working fine. Then, the next day it just stopped working. I took off the panel, checked wires visually, then we on to check the breakers. Everything looked okay, but I cannot say for sure. I went on to find that I need a security code, but I can't even remember if I got a remote for this thing, because I guess it's required. (I even had one of my car tech friends (he's in training) take a look at it and he didn't know what to do.)