I'm trying to get an older PCI Geforce FX-5500 to output to a TV as
its only display - however, when booting, I'm coming up with a black
screen. The motherboard defaults to AGP, and when attempting the same
thing with an AGP card, it displays without a hitch through S-Video.
With the PCI card, it's not even displaying the POST screen.

There is an option in the bios, "Init Display First", which has the
options of 'PCI Slot' and 'AGP Slot'. I've attempted setting this to
PCI slot, booting with both cards, booting with only the PCI card, and
just about any other combination I could think of with no results.

Any ideas or advice for troubleshooting?
I can confirm the card is functional, it shows up in the device
manager when installed alongside other cards.