Yup. My diagnosis was correct.
Trickie-Dickie doesn't have them, but they did have a multimeter and tested it. The needle didn't move!
So now I have to see if Jaycar's got one. (A power supply transformery thingy - I know, the technical stuff isn't my forte!)
Jaycar's wayyyy out of my way.
I only bought the scanner on 3/11/05. Grrr.
Might be cheaper to get a new one... I'll have to see what my options are.