yours is also a bootleg model, made clear from the "COMPUER GAME CONSOLE" sticker and the blanked out copyright information, so id be careful whe experimenting with voltages, it could just use a standard format for cables aswell, most bootlegs do, but it really just depends on what year your model came out in and stuff...
so take back what i said, idk if your gonna find a manual for this, probably never came with one in the first place,
heres what the bottom usually looks like (on a licensensed one)