It's for those who have dead Tablet with this motherboard(PCB) or for those who already killed their own (maybe for customers too)
Download the 2 archives you find 4 firmwares at all(2 Firmware per archives)
Link:BM750 A33_??????|??? ??-?????
Be Smart,Learn And Share
P.S : Do not do it on working tablet cause you can endup with a bricked one....
A23 BM750 firmware can works on A23 BM739 too use it if needed (find A23 BM750 on other thread)