A significant number of Wi-Fi cards were / are defective. If you found a replacement, I would like to know where, too. There are 2 screws for the top of the left side panel which will allow it to hinge downward to access the circuit board.

Using the onboard display, go to Wireless. Somewhere you should be able to print a Diagnostics page. This should tell you if your Radio (more commonly known as Wi-Fi) is turned on and is working. As of April 2020, it said that my Radio was not working and I found out many of the cards were defective.