Wifi could have the following issues:
- Wifi is On and Off
- Wifi is Slow
- Wifi says no hardware installed
- Wifi Cable
- Wifi not connecting to Internet
All these issues could be cause by liquid damage or physical damage due to drop or a shock to the device, or moisture that causes corrosion to build up under the chipsets on the wifi cards over time. When your wifi is not working, it is recommended that you get a Professional Cleaning on your whole device, when you take your macbook to a store for such repairs. Most shops offer half price Professional Cleaning when you take your device for any logic-board related issues. Check the Macbook Repair Shops in Toronto and ask them for a Free Estimate on the repair.