Unlike a lot of modern consoles, the original Gameboy Advance doesn’t have a backlit screen, this can make it a little hard to use in some places. Can you see the screen in a well-lit room? If so, you might just be experiencing expected behavior. It’s not incredibly uncommon for people to buy the screen from a newer Gameboy and [https://www.youtube.com/watch?v=sYiZQZI-P5E|swap it in] to make these old consoles more playable.