Depending on a number of variables (including bandwidth and speed of SD card), the updating phase after you've entered the PIN code can take some time. In some environments it may take up to 30 minutes, but normally it's closer to 5-10 minutes.
If this is taking longer than 30 minutes, we would recommend that you do is as follows:
- Re-download the disk image from the 'Add Screen' page
- Verify the MD5 file (more information on how to do that can be found here)
- Get a brand new Class 10 SD card
- Flash out the disk image to the new SD card
If this still fails, you might also want to:
- Try flashing out the disk image on a different computer and/or using a different SD card read/writer
- Make sure that the network requirements are met
As a last resort, try our USB debugging tool.