Did you already try to turn everything off and back on again?
What exactly did you do when trying to flash your firmware and what program did you use?
A blinking LED on a NEC burner means that the drive is in safe mode. If the main firmware is inconsistent, the drive cannot switch back to the normal firmware. If flashing just failed before anything was really changed, it should help to turn off your drive for a few seconds.
If that doesn't help, you'll have to flash your drive again - this time not using the enclosure but attaching your drive directly to an IDE interface.