Lumia 520 dead while updating from Widows phone 8.1 to Windows 10 phone. What can I do?

[Windows Central Question]

Lumia 520 dead while updating from widows phone 8.1 to windows 10 phone.

I tried to install the windows 10 phone preview for developers, After downloading the updates and while installing the software it was fine till ~60 % of the progress, but suddenly a :-( appeared and the phone restarted, But after that whenever the phone starts, the setup progress bar appears, and after about a minute the phone restarts again, also i am not able to connect to the pc via data cable. can anybody suggest how can i continue installing windows 10 or revert back to my previous OS?
Thank you.

 

[TechFreak1]

Re: Lumia 520 dead while updating from widows phone 8.1 to windows 10 phone.

1) Hold the volume down and power button until the phone vibrates and then quickly press the volume up button. This will initiate the bootloader where the Nokia logo will appear at top and the screen will be red/burgundy in colour. This may take a few attempts.

2) Plug your phone into the your PC and run the Windows device recovery tool.