I was given a Scanjet 3400c scanner by someone who told me it was in "mint condition." Unfortunately, I was misled, and I need to at least give fixing this white elephant a try before I give up on scanning.

I've eventually managed to get the thing recognised by Windows, and it links in to the scanning software OK, but when it scans, no image comes up. I've run a self-test and ithe carriage moves fine, so it looks like the sensor (or connections) might be faulty.

Does anyone have any idea how I can go about checking this?