it seems, you have mixed up Sony DW-G121A (this can be xflashed to SHM-165H6S) with your DW-Q520A. You never can't flash a firmware to a notebook drive. And there are only few drives, that can be upgraded to DVD-RAM and/or Lightscribe capablities.
Do you have a correct firmware file for your drive at hands?
Is your drive still recognized? If that is not totally dead, then you might try patching your original firmware with flashfix and install that patched firmware.
Or you may have a look at XSF on the codeguy's website.
For both, you need original firmware for your drive.
If none of those options work, then you'll have to buy a new drive.
btw: This should have been posted in the Liteon section. You can ask a moderator to move this thread there.