WELL I HAVE CORRUPTED HARD DISK 320 GIGA AND IT IS NOT WORKING ANY MORE I THINK THE CYLINDER HAS TROUBLES SO MY QUESTION IS ABOUT IF I CHANGED THE ELCTRONIC BOARD , THAT WILL HELP AND MY HARD IDSK WILL BE IDENTIFIED AND I CAN ACCESS MY FILES AT LEAST FOR ONCE?

I have had drive failures due to the PC board (controller) on the drive failing, and this was possible, but it is unlikely. You would need to purchase an identical drive and swap the circuit boards to see if that works. If not, then you are SOL for recovering the data. Been there, have bruises on head to prove it! :-)