REMOVE DISC from this drive
It must be run from pure DOS (not a DOS window).
So get out the floppy disks.
You mentioned that the DOS version of MTKFlash didn't work for you.
Did it give you an error at all? Ie: unable to write to bank 0 etc ?
The main reason it wouldn't work would be an incorrect switch or it may not like the .HEX file (convert it to .BIN). HEX EDITOR/CONVERTER
MTKFlash does a forced write, even if the drive is not seen by the BIOS.
providing the LG is Seconday Master:
MTKFLASH 3 W /B J82L822A.bin (I think it will work with the HEX file too). Or try: MTKFLASH 3 W /B J82L822A.hex
otherwise, you'll have to convert the HEX to a BIN. Note the DOS spaces between switches.
it takes about 5 minutes to write to the multiple banks.