I just purchased a gnx3 on ebay and cant get to setup. I downloaded the manual on line and I can't even get started. The power works and I have everything plugged in corrctly. I go to setyupo the output and it won't stop scrolling the options for me to be able to pick an option. Is there something I am missing here. I hope I can get this to work. I have read many reviews and this system seems to be the preferred. Thanks for you hep