I had to do this recently on an old Dell XPS 9530 circa 2013. It had been sitting in a cupboard for a good year or two and when powered on it produced no video

I had to do this recently on an old Dell XPS 9530 circa 2013. It had been sitting in a cupboard for a good year or two and when powered on it produced no video output, or BIOS/POST screen. The backlight for the screen didn't even come on. While it wasn't particularly easy to troubleshoot. I eventually managed to flash an uncorrupted version of the BIOS over USB and it's been working fine since.