No light

When I started the software for the scanner, I get the error message "Couldn't find scanner on parallel port."  I checked the screwed on connectors, and they're all attached correctly.  The power line is pushed in the scanner, and I connected the transformer end to a power cable (checking whether the surge protector was the problem).  Results: The scanner doesn't turn on it's small light up front.  The scanner "light assembly" is half way across a full scan (I didn't know it had gotten stuck when I stopped using it a few months ago).  No light from the scanner light bulb.