Did you get it working yet? If not:
Does anything happen when you try to power up the rig remotely?
Are you trying this over a LAN for now?
I'm sure you have tried this already in your attempts to make it work, but on one of my setups you have to press and hold the power button, then the SIP light comes on and you have to press the power button again to get the radio to come on. This doesn't always happen, but quite often on the one setup. It becomes natural to "start" the radio that way after a while.
Also, I'm sure it was just a typo, but the 6 pin cable is the ttl and 8 pin for the mic.