Phantom 3A not connecting.

Hi. Any help appreciated. Phantom 3A not connecting with RC. Controller can gimbal on drone but thats it. RC doesnt seem to recognise anything put into usb connection. Have tried connecting to app via a Samsung phone and an iphone with no success. App keeps saying ‘how to connect’. When powered on, it just flashes the red LED light.
Any input much appreciated. Thanks.

This sounds like a linking issue. It may or may not be with the limited information you supplied. First, try another USB cable. If the issue persists, see this link: Link P3A

Sorry. We have tried mutiple cables with no luck and cables work just fine for connecting phone to laptop. I will check the link out. Thanks.

The aircraft and RC, under normal circumstances should never become un -linked. Unless you have made firmware changes… That could be part of the issue.