How to troubleshoot when the wireless network card on CentOS 7 is not working?

If the wireless card is not working in CentOS 7, you can try the following solutions:

1. Check if the wireless network card is recognized: Use the command ifconfig -a or iwconfig to see if the system recognizes the wireless network card. If there is no information about the wireless network card displayed, it may be because the driver is not correctly installed or loaded.
2. Install the wireless network card driver: If the wireless network card driver is not installed or loaded correctly, you can try reinstalling or updating the driver.
3. Enable wireless network card: Use the command “ifconfig wlan0 up” or “ip link set wlan0 up” to enable the wireless network card.
4. Set up a wireless network: Utilize command line tools such as nmtui or nmcli to configure wireless network connections, including SSID and password information.
5. Check the network settings: Make sure the wireless network card settings are correct, including IP address, subnet mask, gateway, etc.
6. Restart the network service: Use commands like systemctl restart NetworkManager or service network restart to restart the network service, ensuring the wireless card settings take effect.

If the above methods still cannot solve the problem, it may be necessary to further check the system logs for possible error messages and try other solutions, such as updating the system or upgrading the kernel.