So this is the first Raspberry Pi that I've ever had trouble with. I'm using the official PSU, the official keyboard, mouse and video cable, and a Dell U2515H display but… my Raspberry Pi won't start. I'm using a Sandisk 64GB Ultra SD card with Noobs - freshly setup and freshly installed. Oh, and I've also followed the instructions to reflash the firmware. The result is always the same, and I'm out of ideas.
So what's the result? Well, the screen stays black and the red and green lights are solidly on. No blinking. Nothing. Solid lights and no action at all.
What should I try next?