Taken on a small group of Islands in the Oslo fjord, called Hvasser. A 15 meter peice of fabric playing in the wind, scanned right to left in 21 seconds. Got really lucky with the clouds this time, allowing a single beam of sunlight in as a highlight.
So, I re-installed the prism, luckily it just slots back in. I'm not sure if it helped at all, I still get the much the same result most of the time.
I did manage to get this result. It's black at the top because the lid was closed. I opened the scanner half way thru, and the scan turned white. Then I waved the torch over the sensor and got a definite zigzag. And there's a hint of grey in the middle, which is encouraging.
So, the sensor is still working, it's responding to light, just not in a usable way.