Blue screen appearing on upgrading 8.1 Cyan update Developer preview on Lumia 820

[WPCentral Question]

I got a Blue screen describing "If you'd would like to know more, you can search online later" while i was trying to update my Lumia 820 to 8.1 Cyan update using the preview for developer app. Initially the geared appeared then all of a sudden everything stopped and this blue screen appeared with the above message and since then my phone is just dead showing this evil blue screen. Tried to soft reset and hard reset as well but still it loops back into the same screen. It's been 1.5 hrs now still the same issue. Please advice immediately !! Thanks !

 

[MDK22]

Use Nokia Software Updater / Nokia Software Recovery Tool (installed to a PC / laptop - connected to phone via charging cable) to flash the appropriate software for your device.

Some people have had issues with either of these programs, there are threads all over these forums with possible remedies. I had NO issues falling back (from Dev Preview 8.1 to Official 8.0) to take Lumia CYAN upgrade ... so, I can't speak to these issues. Other than :

• make sure you use the cable supplied with the phone, just because the cable charges the phone does NOT mean it'll carry DATA
• You may have to try different USB ports on your laptop / PC - there seems to be an issue with USB 3.0 drivers
• Install the latest version of the selected tool (NSU or NSRT) (uninstall any existing programs).
• one of those works better with a dead phone, not sure which, you'll have to experiment
• PATIENCE helps - this process takes some time, with scary pauses in the process ...
• SEARCH these forums (or XDA Devs) if you encounter issues - there are multiple threads addressing this
• When / IF you finally get the phone flashed - do NOT sign in, HARD RESET your phone, again ... then sign in to access any backup available. (or NOT, but this'll work better).

GOOD LUCK - hope you have a backup, cause your phone will be wiped