1. Check that the power cable is connected securely and the router is powered on.
2. Check that the wireless network credentials (SSID and password) are correct.
3. Check the Internet connection at the source (modem or gateway) is working properly.
4. Check that the link lights and the router's LEDs are correctly lit up.
5. Connect an Ethernet cable from the device (PC, Laptop, etc) to the router to check if the network connection is stable.
6. Check for any available firmware or driver updates for the router.