Pixhawk 2 Cube with Futuba 14SG error

I been using Pixhawk 2 Cube with a Futuba 14SG Radio on my Tarot 650 Quad. However, today unfortunately, When I armed the motors, the Pixhawk 2 went bizzare and Started sounding different tones. The Motors started rotating at high speeds and No Input from Radio seems to work. I tried to disarm the Quad but unfortunately nothing worked. The Mission Planner which had a link over telemetry, showed “NO RC INPUT”. I had to Switch the Quad off, by pressing the Safety switch on the GPS. However when I checked the RC reciever, it was complety binded with the TX.
Upon Power cycling the Entire System, the Mission planner kept displaying “NO RC input” throughout, not even allowing to try arming the Quad.

When I tried to replace the Futuba Radio system with AVionic Radio System, the Autopilot and Mission Planner recognized them and the Quad was arm able.

What could be possibly wrong?

post a log file so we can see what happened.