Microsoft gets to the bottom of Windows Phone Recovery Tool Lumia-bricking glitch
Yesterday we heard about a nasty bug affecting some Windows Phone users who were attempting to give Microsoft’s Windows 10 Technical Preview a spin. Users with certain Lumia 52x-series handsets were finding their phones rendered unusable after playing with the preview, when trying to move back to Windows Phone 8.1. As a result, Microsoft halted distribution of the preview to devices like the Lumia 520, 525, and 526 until it could work out what was going wrong. The preview’s still on ice for these models for now, but Microsoft may have already solved this mystery, as it explains today.
The problem appears to be with how the Windows Phone Recovery Tool was attempting to write to the storage on these phones. It was throwing too much data at the devices, too quickly, and the flash memory just couldn’t keep up. When writes ultimately failed, users were left with non-responsive Lumias.
Making the glitch so difficult to track down was the fact that not all phones were affected; one Lumia 520 might downgrade without issue, while another would choke on all that data. And there hasn’t been an easy way to know which phones would fail beforehand, until they actually did.
Microsoft has already updated the Windows Phone Recovery Tool to send data in smaller chunks, and do so much more slowly, so that phone hardware can successfully receive it all. The company is still testing things before it starts making the preview available again, but this sounds like a big step in the right direction.
If your phone is already bricked, this updated WPRT might just save it – though it also might not. Microsoft offers some advice for users to try in order to restore their phones’ software, but nothing’s guaranteed.