I apologize if I'm insulting your intelligence but have you inserted the bind plug in the spektrum radio? I have the DX4s and unlike any other radio I use, that particular one requires a bind plug to be inserted into the batt connector before the radio can be bound.

1. Insert plug into batt. I'm not sure but I think it just shorts pin 1 to 3.
2. Turn receiver on
3. Wait for light to flash on receiver
4. In bind menu on Spektrum scroll down to "bind" and click "bind". It should beep and the flashing light on the receiver should go solid.
5. Turn off receiver.
6. REMOVE THE BIND PLUG.