The screen was dead - backlight. So I thought, just remove it and use a monitor that I know works with the computer - it's old now and I can retire it as a desktop. Plenty of useful write-ups on screen removal - seemed fairly straightforward and I don't think I screwed up. But of course it won't power up anymore. So maybe I did do something stupid or maybe the various feeds to the screen are not happy sitting idle? Any help please!