C3700 connection

I have recently started having trouble with my router model C3700-100NAS. My devices (phone and laptop) connect to the signal. However, when trying to get onto the Internet the eventually times out and gives me an error message that there is no Internet connection. The network diagnostic report says it's either the device or resource. Was going to do a factory reset but can't find the reset button on the model that I have. Willing to listen to any suggestions. Thanks.