yes, yes, you are all right... for what it's worth, when I installed Yosemite, I couldn't do wifi ever, even though I had an airport time capsule and another one to extend the wifi signal, I couldn't set it up, and the card was installed in there. I could do Ethernet when the cable was plugged into the back of my mac, so Internet was working. How did I solve it ? simple, I cussed and swore, and waited until Mavericks and later came out, installed that and voila problem solved. Could set up wifi, card was detected by the OS, everything working tickety-boo. Your MacBook Pro will support El Capitan, jamesramos, but not Mojave, and probably not High Sierra (if that's even available anymore....maybe it is) , so if you can, do a backup on your MacBook pro . It's a good idea to have a backup system in place and use it regularly. After that, as Ruskes said so well, you have to reinstall your OS to fix it and the network card drivers. You can do this by rebooting and holding down the Apple (command key) and R together on reboot. Before rebooting you should also have the Ethernet cable plugged into your MacBook from a working router/modem. hold down those 2 keys on reboot until you see a language selection screen. Choose your favorite, then click on continue. You should be able to re-install the OS. Yosemite isn't available any more (unless you already "bought" it from the App store previously) , same goes with Mavericks. It should let you install El Capitan. Do so. If that doesn't work, then just restart your MacBook, go to the App store, sign in and grab a copy of El Capitan and install it. hopefully that may fix your problem. You might also want to run the Hardware Test as well, or start up in safe ((single user)) mode-hold down shift key on startup, loads the most basic of stuff. hopefully the hardware test can tell you something. If you have a bad airport card, about the only way to fix it is to replace it. Or--plug in a USB wifi dongle in the side that supports Mac. I don't know how you managed to get in there and re-seat the cables to the airport card itself and all the other cables as well, there are a ton of them, and getting to the airport card itself and on top of that, re seating the antenna connectors and the camera connector going to the airport card and not ripping or breaking anything at all....well, if you did that and it still works just fine, well, my hat's off to you.... I salute you, sir, because that is some mighty difficult work. Getting in there and replacing it is possible, but it is very very difficult. A new airport board would be about $80 and would get you 802.11 n speeds. 4 gig ram modules for this are about $40 each----and the most ram it can have is 8 gigs.
just my opinion
John B
