puck lite problems

I did the test without anything connected and with the resistor still connected. When it was still connected, it looked pretty much the same but it also said:
"LED2 pullup voltage out of range (0.542...) - disconnected?"
and error code was LD2, not L30

The LED still worked when I set it high.

Looks like the self-test backs this up too. Interestingly though it looks like D30/D31 may have ended up partially connected together as it seems like if D31 is floating, D30 can still read a value?

I'm not sure exactly what you mean here. D30 reads ~0, but with everything disconnected I'd expect that. Do you mean for me to try this on a board that hasn't been desoldered?

The circuit is as you described. For future versions I will put one side on ground. As far as water/sweat damage, I can't rule it out but it seems unlikely. I will try to get a picture of one of the setups posted.