Why did my console stop working?

Hello!

I'll cut to the chase.

Yesterday I dug my Sega Genesis out of my closet. It was on the top of the pile face up, it still has the dust protector and everything.

Anyway. After hooking it up, I put my one game in, sonic spinball. I played for an hour and a half then just hit the power button to turn it off.

Today I have a friend over, and I want to show them the Genesis since they've never seen one before. I turn the TV on and, what I believe to be the copyright screen, or the screen before the "SEGA" logo shows up. But after that screen, it fades and stays black. And doesn't load up the Sega screen. Or anything beyond that. No music plays or anything.

So I hit reset. Same thing.

Then I pop the cartridge and do the standard "lightly blow to dislodge dust". Pop it back in, still same results. Hit reset again.

This time, I don't even get that copyright screen. I get nothing.

Now I'm not sure what to do. Because I don't have other games to test with, and I don't imagine a game goes bad overnight.

Help?