I was asked to upgrade a system in order to be able to add a third monitor. The system, an older Dell Inspiron 620, would need a new video card, power supply to power the card and the assorted cables. Those were ordered and installed, but on power up there was nothing but a black screen.
As it turns out, most cards now don’t support operation in a legacy bios, but rather require being installed in a machine with a UEFI bios (what is now industry standard). Previously, cards were shipped with dual capability (legacy and UEFI) so this was never an issue.
Learning something new every day.