Must be a Corona board that you have, but is it a 250GB HDD type or the 4GB one? Cause the 4GB requires a different kit to read and write the NAND compared to the standard 250GB which comes with just 16mb NAND onbard. Either way you'll be looking roughly for around £50 - £70 for a complete job which involves replacing the PCB and decrypting the NAND to extract the necessary files needed to create either LTU2 or Matrix custom firmware for that drive.