well I botched that board up good wrong part pulled there was a second k fuse and that was the one. well it still came in handy for repair of my primary h520 that fell out of the sky after a 90 degree flip. just transplanted the mainboard using the one on the h520 that fell from the sky after confirming that board was still good working shape. so now i down to one fully working h520 with no major backup body parts. (still got 4 good arms 2A and 2B and 2 good landing gears, gps hood, wifiboard, 2 antenna wires, 2 retract boards. on off board, sonar board) not sure i can mount a 520 board the a h480 body frame yet without modding the h480 frame yet. waiting on the h480 plus hoping atleast they will sell parts in the USA for that one and I hoping the mainboard uses the same connection for the flight controller and all I have to do is switch main fc and got my second h520 back.