I have an LC III that I had recapped, both the power supply and logic board were recapped and cleaned, on receiving it back everything worked with flying colors, but now (only a week later) the internal speaker isn't working. I've tried zapping the PRAM and booting from a different hard drive to rule out software issues, also the headphone jack in the back works if I plug in some ear buds. What do I need to go over next?
The simplest thing to do with your LC III is plug in external speakers and not worry too much about it. The LC III supports stereo sound so external speakers will sound better than the internal speaker anyways. Once I damaged the headphone jack of a PowerBook and the tech at Tekserve noted that I could either replace the motherboard for a few hundred dollars, or plug in a USB headphone adapter for twenty bucks, good advice then, and still good advice.
If memory serves the LCIII uses a 2 pin 4ohm speaker. Is it possible you simply didn't reattach it the last time you had the board out?