I try to upgrade My Book Live Duo and made one big mistake! I've upgrade bash to 4.x version. As result my NAS stop work's.
Then I decide to restore it by connect to UART port, placed on board.
First of all, I can't find so quickly as I want needed connectors. If you want to use UART - here are part number's for onboard male connector - you need to find female connector named MU-4F or PHR-4.
Also you may use connector MU-3F (to plug to UART without +3,3V plug).
Also you need some kind of UART TTL shift chip. If you hav't real COM port - than use USB-UART translator (like MAX232, CP210x and so on)
I've used ready-to-use microplate (almost ready :) ) based on cp2103 chip with VCP driver from SLAB (virtual tty port).
Second impotent topic - when you connect to UART remember to connect RX from you microplate to TX on wdc board. Also connect TX from you microplate to RX on wdc board.
AND most impotent - when you use terminal (console) software - turn off hardware flow control. Use only software flow control!!! Without it you will only view boot-log without give to console any keyboard command.
BR to all!!