Had 250gb Hitachi Deskstar. Was using it as portable and dis not have plate over circuitry (big mistake?). Was working fine with my usb adapter and driver on both old and new systems. Usb adapter and driver works fine on other drives still. Suddenly the Hitachi will no longer respond to the loading usb driver and is not recognized by 2 independent systems. No error message. No noises or clicking from drive, sounds normal spinning up. I guess I must have touched the circuitry and destroyed the controller? Is that the reason?