Hello, I bought Happymodel - 4 in 1 FLIGHT CONTROLLER for ELRS X1 AIO Drone. FC defective. Engine 3 does not turn well. with minimal power, the engine spins, when I give more power it stops spinning. I thought that the problem was in the engine, but after changing another one, the problem remains. and No. 3 engine is very hot. all others do not heat up. My friend has two flying drones with the same FC. We install the firmware as his. The problem hasn't gone away. I think this is a problem with the ESC mosfet.
F44779