Need a wireless mini-card

My computer can no longer connect to my wireless router. I see all the networks in the neighborhood. Diagnostics found nothing. My other computers and smart phones all connect to the router. I believe the transmitter on my wireless mini-card has failed. I bought the Dell computer last August. I will be contacting support. Just want to see if there are other reasons my computer won't connect that I am not aware of. Thanks for your help.