Ubuntu 18.04 wireless connections visible but won't connect BCM43602

Here is the solution which worked for me with a Broadcom 14e4:43ba:

sudo apt-get purge bcmwl-kernel-source
sudo apt update
sudo update-pciids
sudo apt install firmware-b43-installer
sudo reboot #note that this will restart your computer
sudo iwconfig wlp2s0 txpower 10dBm

This is just a combination of these two links:

Installing Broadcom Wireless Drivers

https://bugzilla.kernel.org/show_bug.cgi?id=193121

If you are someone who has the same problem as me, I highly recommend reading both of the links, especially if the commands I gave don't work.

Unfortunately, this solution requires internet connection. I had to go buy ethernet and adaptors to use it. One hiccup in that process is that the ethernet was very particular. The first two places I plugged it in did not give me internet. This is likely due to a completely unrelated issue, but if it happens to you, just keep trying different sockets in different rooms or buildings. Good luck!

This worked for me, only one step:

sudo iwconfig wlp3s0 txpower 10dBm

I'm on a 2017 Macbook pro 15'