Could be a bad PCIe slot or the card is busted.
Only thing i could think of is that the card has no power it should show up in your system device manager.
Either see if you can find other PCIe slot that is compatible.
If you have a other PC see if the card works, if it has a fan just by making sure the fan spins.
With a heat sink just switch on the other PC and see if it shows up in device manager.