Error in bootable option

[Mohamed jaffer]

ERROR:Unable to find a bootable option.Press any keyto shut down. Like this coming in my lumia 520 in service centre also they said cant solve the problem.but i wwant to ON my phone.If any solution have????

 

[anon(10197358)]

@Mohamed jaffer

ERROR: Unable to find a bootable partition. Press any key to shut down.​

indicates that the bootloader is KO. Nokia Care Suite (NCS), thor2, Windows Device Recovery Tool (WDRT), Windows Phone Image Designer (WPID), etc. can't do nothing. Using of a JTAG box is required, or motherboard changing is required if you want repair your Lumia 520.