Agilent DSO3102A UART Pinout

[franksretrolab]

Hello, I have an Agilent DSO3102A that has stopped booting.
I am looking to connect a CH340 so that I can view the logs.
I searched through and read many forum posts, and the only one I could find a post that had a photo of the pinout for the 3000X.

I found a header on this board marked J12 and I tested a couple of the pins to ground to see if it was like the image and it was not. 
Pins 2 and 10 seem to go to ground....so I am trying to figure out which pins would go to Tx and Rx.
I have attached a photo of the board.

I am new to this so please forgive me if I am missing info, etc.

Any help would be greatly appreciated.
Thank you

[DavidAlfa]

From the adsp-bf531 datasheet:

81 TX
82 RX

Try tracing those pins to the 14-pin header, seems to be routed there, also the JTAG interface.