Alright alright, obvious to someone who knows what they're looking for
thanks for the info. I'll go take a closer look at that now.
Edit: Okay I just had a homer simpson D'OH moment when I turned the board slightly and noticed that I could see the photodiode component from the new angle. It doesn't appear to be controlled by an IC though, and it seems to have several different components, so it doesn't look like I'll be able to salvage this. I think I may have an old TV somewhere, I'll see if I can salvage the required component from that.