I haven't been able to participate on this for a while.
First of all, board has been powered mostly from USB, sometimes with a lab power supply, which has a variable voltage, but I've been using it with 12V.
I found the schematic for the board(on the product page, what a surprise
), and have been doing some trouble shooting with it, and it looks like the IC7 just has gone bad for some reason. The FET it drives is ok and working fine, and the resistor and LED are fine ok, led lights up when driven externally. The 3.3V regulator is also working as expected, which really shouldn't be an issue, because it's behind the FET but checked it anyways.
For now, I just removed the IC7 from the board, and have to live without that 3.3V when on USB power. Maybe I'll get a replacement IC for it later.