My old bench boss in Dayton told me to stop swapping power supplies first, and he was right
Back around 2011 I worked at a small repair shop in Dayton and my boss Ray kept saying to test the RAM before anything else on a no-boot machine. I thought he was stuck in the past, but after I burned a full day on a dead power supply that tested fine, I started pulling sticks first. Nine out of ten of those calls turned out to be a bad stick or a dirty slot. What's the first thing you check on a no-boot box these days, or does it depend on the board?