No old electronics. They are all over in electronics. Did you test that wire with a multimeter? Also I have an apm 2.6 and tested your jumper wire solution and my 2.6 worked with a wire…
I don’t know if the 2.5 is much different. It is something simple in the settings. Your values change when you power on your TX. maybe do like you said and flash it with rover then back to copter.
alright. so i tried with an actual jumper and i also tried flashing with rover then reflashing copter. and the radio still doesnt send any signals to the board. is there anything else that would fix this?