I'm not sure whether to post my issue in this thread or not. I have the same issue under similar circumstances, but I will describe my issue and what I have already done to try and rectify it.
I have a Dell Latitude D820 with a Dell 1390 WLAN wireless receiver. The Broadcom model for this receiver is BCM4311, and is one of the models listed in the supported wireless driver package that needs to be added after installation.
In Zorin OS Core versions 3 and 4 my WiFi receiver worked after I went into "Add Hardware Drivers" and it came up with the Broadcom STA Wireless driver package. I would activate it and presto, WiFi power light turns on and the OS sees my wireless signal.
In this new version, 5, I went through the exact same procedures after installing the OS (64-bit). I had it search for the package and just like before it found it. I clicked on activate and it went through the download and installation. After rebooting (which it said I had to do in order to activate it) the OS would load, however after the desktop appeared the WiFi light did not turn on (and yes, my power switch on the side of the laptop was turned on). Without the power light turning on there was no way for the OS to see my wireless signal. I went into the "Add Hardware Drivers" section again. It showed the driver as being present (active) and IN-USE! Well, the OS may think it is in use, but it isn't!
I even tried some of the other steps recommended in this thread but nothing worked. I tried completely reinstalling the OS from scratch again, going through all of the same steps as before, and I ended up in the same place, no working WiFi. I also tried the option to Install "Windows Wireless Driver" in the control center. I downloaded the driver from Dell and copied the files into a folder on my desktop. I clicked "Add" and found and clicked on the .inf file. It said that it installed the driver and that the hardware was present. However, the WiFi light never came on and there was no wireless connection. I went ahead and deleted the driver afterwards.
It would seem to me that because I had no problems with the WiFi working in previous versions of the OS, something may be wrong with the new driver for OS 5.
Any help in resolving this issue would be appreciated very much. While I can use the OS while connected through a wired connection without any problems, I really need my WiFi accessibility to work.
Thanks for the help!
Dr. Stephen W. Pardridge