Q: Network Problems with MacBook Pro 15"

I really appreciate your offer of help, and I printed out those pages and walked through the steps.  Unfortunately, in Safe Boot and in another user account, the computer continues to see my active router and network but refuses to connect.  First, it says "None of your preferred networks are available," as it clearly displays my network on the list of available ones.  Then when I attempt to sign in it says, "The Wi-Fi network "xxxxxx" could not be joined" and suggests running diagnostics.  It is strange that the computer clearly sees the strong signal my iPad Air 2, HP printer and Samsung Galaxy S7 use.  It keeps fluttering, scanning over and over again, turning up my network and refusing to sign on.  I have a ton of multi-page "diagnostic" files, but none of them result in any useable suggestions. 

My driver is com.apple.driver.AirPort, Brcm4360.  I wonder if it is incompatible with my router?

Maggie2012

Good idea, and I saved the resources.  But without any internet connection (except

on my iPad Air 2 and my Samsung phone (on the same network), I could not pursue

most of the diagnostics for this computer and El Capitain 10.11.6, even with the

Apole Care specialist helping me. 

I always learn from the community's kind help, even when it applies to future situations but

does not work in this one. Gratias.

maggive 2012

Thank you, Grant.  Very helpful pushing option and Wifi button.  My display is very different from

yours, but I do not have wifi on the computer, so I cannot send a screen shot.  I am trying a photo from my phone, sent to my iPad Air 2.via email, then photos, 

There are a lot of networks and the symbol next to my network is all bars strong.  The computer sees it but says "Your preferred networks are not available," until I type in my network and password, when it erases the name, then pauses for a while, then says, "The Wi-Fi network "my network's name" could not be joined.  The router is two feet from the computer. The iPad I am typing on and the Samsung phone work very quickly with the network even three rooms away, in my waiting room.  As you can see, I get nothing for PH mode, RSSI, and Transmit Rate. 

In one of the gazillion Diagnostic Reports, a selection of "wifi.scan.txt" says

"My network' <5268696e 4f32>,

bssid=28:10:7b:a8:6c:3c

channel=[11, width=20], cc=(null), type=11n,

rssi=27, rsn=[mcast=ages ccm,

ucast={ aes. ccm }, auths={psi },

capps=0xc] wpa=(null),

wep=no, ibss=no,  ph=no, swap=no,

hs20=no, airport=no

Since I started replying to you, my printer has stopped responding to the computer, although it had a great connection

before (WiFi until that stopped working, then USB, and now that has stopped).  This is my business computer, and I need to have a working computer.  Thanks for helping me to establish what is what.

Maggie2012

P.S. I tried mightily to mark all the efforts to help me as "helpful," but the icons will not change.

Perhaps it is because I am working on an iPad Air 2, in the absence of wifi on my MacBookPro.

I Really appreciate all of your efforts and the new learning.

maggie2012

Followup--  HARDWARE PROBLEM!   I still had my accounting for the month to do and client files to scan,  bills to print,  several hours of work to do when the computer gave up several more shreds of pretense to be the sleek,  mean machine it first appeared to be.

Printing functionality quit,  even via USB (even though phone and iPad continued to send to and operate the printer.)

I finally faced it -  THIS IS A HARDWARE PROBLEM AND A SYSTEMIC PROBLEM.!  So that I would not go nuts with anxiety about undone work on my last day at work before a two-week European vacation,  I STARTED UP MY SUPER-DUPER BACKUP DRIVE AND FINISHED MY WORK ON IT.  Of course the backup drive could not give itself wifi  capability.

But It did run the printer and separate scanner in both Mac and Parallels 12/running Windows 7.  And it let me file and take care of all kinds of business.   What a disheartening two weeks wrestling with a faulty new machine.   What a good save from a 1TB Seagate Thunderbolt backup drive and a 3TB Seagate Thunderbolt Time Machine!

Thanks to all who listened,  prompted,  suggested and helped.   I am glad you are there and bummed that I got a defective machine.  I have an appointment  to turn it over  to Apple to fix [not likely]   or replace.

maggie2012