It loses signal, won’t link to the controller, or the video drops.
Antennas damaged in a crash, or mismatched firmware between drone and controller.
We update and re-link them; if that fails, we replace the antennas.
It depends on the model and on what we find inside, so we quote each repair individually. The diagnosis fee depends on the device, and you approve the exact repair price before any repair starts. If it can't be fixed, you only pay the diagnosis.