it has been my experience using numerous nec dvd/writers exclusively in toshiba laptop computers, none of which successfully recognised the drive at boot up i was left with 2 choices.
either ATA reverse flash using liggys method or solder a connection between pins 45 and 47.
i have considerable experience with computers. flashing, writing machine code, programing as welll as the physical aspects of dismantling and restoration and repair.
it is my own personal opinion the easiest and safest method to get these dvd writiers to install properly is to solder............but NOT the drive.
solder the pins on the interface adapter which connects the computer to the drive.
using this method ensures the warranty for the dvd remains intact and homebased flashing is limited or not done.
soldering the adapter is much easier than the drive and if you screw it up you can always get another one fairly inexpensively on ebay by buying and old basic cd rom complete with caddy suitable for your particuliar machine. ebay usually sells these cheap as no one wants them any more. you can always throw away the drive and keep the caddies and adapters which always come in handy.
i have seen more bad flashes than i care to remember. it is an inherently dangerous undertaking.
soldering unlike flashing can be undone if it goes awry
anyway just my opinion
see my previous posts for pictures of the soldered adapter.