Default Need help sending commands via USB to RS232

Hello:

I have a generic ATV1200 Android box (AML8726-MX) and would like to send Linux commands to the box via Putty SSH. So far I have been able to monitor/observe the boot up via SSH - but haven't been able to actually interrupt boot process and send my own commands. There is a brief moment where it says Hit Any Key to Stop (or something like that) - however, any key I hit isn't doing anything to stop it. From my understanding, I need to boot to recovery or at least stop usual bootup, is that right? I've been referring to this guide (https://www.dropbox.com/sh/1r3anv4hf...%20ATV1200.zip).

I'm only using three wires GND, TX and RX (power for box comes from plug). Is there any chance the TX and RX are mixed up? I don't think that's it because any other way I rearrange the wires either kill the SSH connection or spit out gibberish.

Any help is appreciated.