Genesis loads up shows licensed by sega then freezes
The problem doesn't come from your console, but from your game cartridge. I had the same problem, and I've stumbled upon your question while Googling about it.
Recently, I wrote a tutorial about how to solve this problem which affects most old consoles that use game cartridges, such as the NES, the Nintendo 64 and the Genesis.
The tutorial is in French, so here's link to a translation by Google Translate: http://is.gd/52USF
Please ignore grammatical mistakes, as those are the result of the automatic translation. The tutorial is about NES cartridges, but it works with any gaming system that uses cartridges.