I bought a used Adv bird with a broken yaw arm and cable. It has been flying for a while now without a camera (me and previous owner). I replaced the yaw arm and cable today, following videos very carefully. I powered it up and I wasn't surprised when it didn't work right away. What do I need to check or do now? I made sure the RC and bird were linked, the green light is blinking on the gimbal, etc. I have the NO SIGNAL red bar at the top of my screen. Does the Firmware matter? Do I HAVE to have an SD card in it to make the camera work? Also, I tried using an old micro SD card and it said it couldn't format it, same with a second used one - so I am getting a new one to try. Thanks for the help!