Here's how I did it should anyone else have the same problem:
- Plug in USB lead, power up Tx and gyro/Rx.
- All three lights stay solid indicating no communication, PC software wont connect in this state.
- Press set button once - only yellow light comes on
- Press set button again -only blue light comes on
- Now connect PC software, it should connect ok while the blue light is on.
- Re-set 'receiver type' to 'conventional', update settings and that's it fixed