14 DAY TRIAL // Earlier this week, it emerged that Windows 10 for phones preview build 10051 was bricking some Lumias in the 5xx series after their owners attempted to downgrade back to Windows Phone 8.1. Microsoft reacted quite quickly and pulled the Windows 10 build for these devices, and now, after more investigation has been conducted, the company is ready to share more on the matter.
Redmond says that devices that fail to recover are experiencing two types of behavior, so some are displaying a red Nokia logo, while others are getting a black screen and they're fully unresponsive.
While the company says that only “a small portion of Lumia 520” has been affected, it also adds that the recovery image that was supposed to be used when flashing wasn't correctly handled.
“The blocks of data were too large for some devices to handle, and the memory on the device was having trouble with the speed at which the data was being written. In short, devices were getting too much data, too quickly. This would cause the failure as the new software is corrupted,” it added.
Not all units getting the error
It appears that not all Lumia 520 that have been upgraded to Windows 10 for phones preview build 10051 might get bricked when performing a downgrade, but to make sure that this no longer happens, the company released an updated version of the Windows Phone Recovery Tool that should correct the issue.
The update is now being delivered to computers running the existing version, and while there's no guarantee that everything should work like a charm on both bricked and non-bricked devices, it's clearly worth a try if you have no other option.
We're seeing reports from users who claim that the new version of the Windows Phone Recovery Tool doesn't make any difference to their bricked devices, while others state that, after trying to reflash for several times, it does work and get the phone back to WP 8.1.
If you're also experiencing the same issues and trying to recover, make sure you drop us a line to let us know if this works or not.
Update: if you can't downgrade your device and you're seeing a red Nokia logo, here's more information on how to fix a bricked Windows 10 phone.