Windows 10 Technical Preview for Phones
Windows 10 Technical Preview for Phones.Microsoft

Microsoft has released an interim fix for Lumia 520 and Lumia 521 smartphones users who complained about their devices getting bricked while trying to downgrade to Windows Phone 8.1, after installing the Windows 10 Technical Preview for Phones update.

The Redmond-based company has stated in an online post that the Lumia 520/521 users who reported the bricking issue can obtain the interim fix, but has not clarified whether it would unbrick phones.

Engineers at Microsoft have also stated that they uncovered only a fraction of 520/521 users whose phones got bricked after installing Windows 10 Technical Preview.

As a result, Microsoft has started rolling out an updated WPRT and users need to simply close and re-launch the old WPRT and it will update to the latest version.

"Before we re-enable the update path from WP 8 to Windows 10 Technical Preview for these devices, we will be reaching out to users to do a bit of additional real-world testing. Once we're confident in the results, we'll turn the update path back on for these devices," the company said on its forum.

The updated WPRT is likely to temporarily fix the bricking issue, but those who are getting a red Nokia logo on their display screens will have to force a manual reset to get their devices unbricked. Follow the steps below, if you are getting the red Nokia symbol on the screen: (Via Microsoft)

  • Ensure good and continuous power source for affected devices (connected via USB cable that can transfer data and charge the device simultaneously)
  • Close the WPRT, re-open, and take the update to the new version of the WPRT. The new version is 1.2.4
  • Once the new version is installed, re-attempt the flashing process
  • If your device is not recognised, click the "My phone was not detected" button and continue the attempted recovery process.

According to engineers at the technology giant, the reason for the devices getting bricked is: "Data writing size and speed: It was discovered that some devices are having trouble accepting the recovery image data being flashed. 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."

If you have tried obtaining the updated WPRT and if your issue has been resolved, do let us know about it in our comments section below.