Wi-fi stopped working. Can someone help?

Hi all,

My Nexus 5's wi-fi stopped working completely after several days of working intermittently. I've had this phone since it first came out and never experienced this problem. I've done rebooting several times and still same problem. So I think it maybe a hardware issue ... does anyone know how to troubleshoot more or what part to replace inside the phone? I have experience with taking it apart a couple times to replace a broken screen on it before. I'd like to take a crack at repairing it myself before buying a new phone. For now it's still working fine with my T-mobile network data.

Thanks,
- Tim