This amp is listed as parts or not working, only because I cant get it to work 100 percent. IT DOES WORK, its not dead. I hooked it up with a 12v power supply and the sub channel works, the 3-4 channels work and sound good. The 1-2 channel is where its hit or miss...the right channel works all the time, the left is intermittent. Usually tapping the amp will get the left channel of 1-2 to run, but not always. All the switches on the back seem to work, I sprayed them with deoxit and work...ed them several times and they seem ok, but again I cant be absolutely certain they are perfect. Gain and level controls throughout amp seem to work. The high current / high power switch and LED works fine. I did not run this amp at full power as my PSU cannot provide enough current...so I do not know how it performs under stress or high loads. It does have some rusty paint and scratches here and there. Was stored in a auto shop and has a oil/gas shop type odor to it. Sold strictly AS-IS, as described.