When one cannot associate with a Wifi Access Point it can be helpful to find out exactly what is going on. Below is the recipe I use to see what NetworkManager is doing:
Start a bash shell as super user:
$ sudo -i
Kill the current NetworkManager:
$ killall NetworkManager
Start the script command to capture terminal output:
Start NetworkManager to run on non-daemon mode:
$ NetworkManager --no-daemon
Try to associate to your Access Point to get some debug data. Then exit the script session:
And then look through the generate typescript file to see what NetworkManager is doing.
Alternatively, one can get some idea of what is happening using iwevent:
Waiting for Wireless Events from interfaces...
07:04:25.174275 wlan0 New Access Point/Cell address:Not-Associated
07:04:57.908360 wlan0 Scan request completed
07:04:57.910007 wlan0 Set Mode:Managed
07:04:57.910038 wlan0 Set Frequency:2.412 GHz (Channel 1)
Hopefully using these methods can give you an inkling to what could be causing the problem!