I have detected these headers in the board 6721W . J5 looks an I2C bus and J4 for mcu programming. It would be interesting to explore J5. Also, I am thinking if TP12 and TP13 Rx and TX would show the messages in 0-5V 
I have detected these headers in the board 6721W . J5 looks an I2C bus and J4 for mcu programming.
It would be interesting to explore J5.
Also, I am thinking if TP12 and TP13 Rx and TX would show the messages in 0-5V