Hello there!
Thing with HGSS is that they had anti-piracy stuff within the code making it harder to emulate those games (more than just the black-screen thing as well). There's patches to find online via google and info on how to set up emulators to make the games playable though in the
Emulation section, and in particular
this thread which is specifically about emulating HGSS so I suggest checking out that thread.
However this section is for talking about the HGSS games themselves rather than how to emulate them (which is what the Emulation section is for), and so hence thread closed. Good luck with getting it to work.