Power light briefly stays on then goes off

I just picked up a Sega Genesis, and I have a power adapter that I can plug into it. When I have it plugged in and the switch on the off position, then put it into the on position, the red light briefly comes on then goes off.

Is this an internal issue? Bad bulb? Bad power cable? Is that how it's suppossed to be? I don't have a video cable for it yet.

Thanks.