This question already has an answer here:
I need help identifying an SMD component it is a small(1 mm X 1.5 mm) black part with an "O" written on top if it. I think it is a Schottky diode for reverse polarity protection ?.
(Source, first part on codes beginning with O)
The component in question is marked J2/J3 on the silk screen. Also, if it helps the image is of a remote control pcb.
PS: This is my first post so please let me know if i did something wrong :)