How I fixed it (or figured out how it works)

So the other day I couldn't resist buying two Priddy books for Baby C - Alien Al and Dizzy Dragon - they were on special at Exclusive Books for R15 a piece. When I got home later I realised why they were marked down so drastically - the sound on the last page didn't always play and for a few days it didn't work at all.

I asked my friend Google for the answer, but found nothing, only disgruntled reviews on Amazon. This seemed like a challenge for inspector Dagmar....

Having a closer look at the mechanism gave me some clues - instead of like those cheap musical cards, it didn't work on a trigger switch built into the spine, but if you look closely there is a little sensor peeping out a tiny hole, which looked like a LED light. I fiddled around and made sure the sensor was positioned nicely in the center of the hole. That didn't work.

Thinking a bit more (which hurt a bit I might add) I deducted that the sensor probably works on the amount of light - so when the sensor finds light it realises the page is open and plays. So, continuing with that line of reasoning, I opened the book somewhere where there was plenty of light (next to the window or next to a bright lamp) instead of the dim bedroom where I usually read Baby her books, and Bingo! It works! Every time. Until the battery runs out that is...