Don’t spend time trying to get a video output before you replace the power supply. I have been working with and on computers for over 40 years and I have a 99.9 percent success rate with solving computer problems. I am so good that I have a full time job doing technical support and I am in high demand. I laugh at Geek Squad. I am a Nerd. Nerds rule! I spent over 15 minutes on your problem and if I was billing you it would be 250 dollars for a one hour minimum. I would order a compatible or identical power supply from Amazon or eBay if I was at all interested in success with your problem. ThenI would charge you another 250 dollars to install it, plus whatever the power supply cost. You’re welcome.