It is fundamental that lspci detect your card (unless it is a usb device). If it is usb it should be detected by “lsusb” (requires usbutils), but you state “card hasn’t moved from in its slot” so I assume then it is PCI. (and hence should be detected by “lspci”)
Did you try booting to fail safe to see if your card is detected then?
Do you have mother board sound? If so, what happens if you switch OFF the mother board sound in BIOS? (in truth, IMHO this should make no difference to the PCI card detection).
Please can you confirm that the card is seated properly? ie. with the power OFF, open the case and confirm the card is firmly in place. Close PC, and try powering it again. If that doesn’t work switch OFF power, and try this with the card in a different slow.
Any chance the card is non-functional? Maybe zapped by static electricity when you were cleaning the interior of the PC ?