For those of us who have
gotten the unlock code from AT&T for our various Lumia devices ...
Thursday, I fell back to WinPhone 8.0 from WinPhone 8.1 Dev Preview so I could download the official WinPhone 8.1 / Cyan update. Process took a while.
When you're done, don't forget to unlock your phone (
my Lumia 1520 was sim LOCKED, again - you're flashing the AT&T rom to go back to 8.0).
- dial
##7820# (this works on my Lumia 1520)
- you'll get the screen w a lock & text box for entering unlock code
- if lock is OPEN, you're OK
- if lock is LOCKED, re-enter your unlock code


