I'll tell you how I managed to unlock my lumia 900 att.
I bought two devices at auction ebay. Turned for unlockfusion. Famous seller unlock codes at auction. For one lumi code sent after 15 minutes, and he came. Two days later, I wrote no codes and returned the money. Began to search on the Internet, came across a topic on xda. They talked about the seller jose70blue on ebay. I found him and his lot for unlocking lumines for which there are no codes. He calculates the codes himself (at least he writes this himself). I paid 19 bucks, sent it and waited. Especially not hoped. Three days later came the code in the mail. I immediately try to enter it. The code is eight-digit. I inserted a SIM card, turned on the device, he requested the code and wrote that I have 10 attempts. I tried and it turned out that the code does not fit.
I thought that the seller did not calculate the code, but then I remembered one video on YouTube, how can I enter the code. I entered the code 10 times, any numbers, just to end these 10 attempts. After that, the phone requested a 32-digit PUK code. Now I tried again the code that gave jose70blue. And he came up. I don’t know why this is so, but first in the first 10 attempts the code doesn’t fit, but only if the attempts end and the phone asks for the PUK code. I am writing this from my own experience, I just unlocked it myself. Here is a link to
lotunlock Only the price is already 29 dollars.