How can you physically tell if a network card is not working?

Answer:
Open the computer case and make sure the NIC is securely seated in the expansion slot. Try reseating the card. Reboot and check for activity lights. If you still don't see activity, replace the NIC, and then install new drivers.

wrong. check in the back of the computer and the front of the router and make sure the lights are blinking
First answer by Krizzlesparkle. Last edit by Hufferman05. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 1 [recommend question].