MVS PCB Questions

Hello all. I have a board and cannot for the life of me find any info on these board designations. Also are there any schematics that identify these? Thanks.

NEO-MVH MV4

J2
J3
J4
CN1
CN2

J2 - I believe if you were to jump it, it would disable watchdog
J3 - Is the 4 pin header that would normally go to an MV-IC board to drive the headphone ports on it. The 2 inner pins are grounds.
J4/J5 - You would think these would be jacks for headphones, but they dont seem to be/work. GadgetUK mentioned in one of his videos he thought they might be audio IN.
CN1/CN2 - player 1/2 joystick ports

Thanks for replying.
J2- I'll have to look up watchdog
J4/5- No one has an idea? Tracing the lines keep it in the audio section of the PCB. When I get time I will play with it.