After all information I have now here's the summary:
1) Ribbon A on Al page is the RGB connector - this is what I was looking for. It carries RGB and sync signals to analogue board
2) Ribbon B on Al page is front controls board connector - it connects to the tiny board at front side of AIO and carries sound and control signals (may be IR as well - but I'm not sure about this one).
NOTE: not all "personality" cards have connector for ribbon A . That means that in some cases of doing Taco - a custom work for changing/soldering to external monitor connector will be required.
