I would just like to add this as a last ditch attempt
hold down the Pencil key then turn on the power if the phone boots then enter *#7370# this will then format the phone back to original state this is for QD only and some times needs to be tried several times worked for Me 😎
also all these peps on about flashing the phone you need a program called Nokia Diego its only availible to nokia repair centers but a cracked version is floting around the web have a look😉