YX8019 Component

[bostonman]

I have some LED solar lights that are having issues. Long story short, I was interested in seeing the circuitry and discovered they have a YX8019.

Looking online, datasheets are in Chineese, but an old EEVblog message has a YX8018 translated that I believe is nearly identical.

https://drive.google.com/file/d/0BwZTKiltzKYzTDJQYjdQMzhNVEU/view

Anyway, looking at figure 1-2 which seems to match the circuit I traced, I'm baffled by how the LED turns off when sunlight hits the panel. If pin 1 pulls the line to ground, that would turn off the LED, but draw excess current from the solar panel and not charge the battery. If the solar panel voltage is higher than 1.2v, which would turn off the flow of current from the battery, the LED would still turn on.

[bostonman]

I disassembled another type and discovered this one has a black dot (epoxy?) on the board. I'm assuming a different component is used and epoxy is placed over for protecting against water/humidity.