I purchased my Phantom 3 Professional two summers ago. It worked just fine for about two weeks then the camera failed although I could still fly it. I purchased a new camera that did not solve the problem so I gave up and put it away until recently. When I lit it back up the aircraft seems to function fine but all I get from the RC is a constant beeping and a flashing red light. I upgraded the aircraft firmware and maybe the RC firmware (you can't tell about the RC firmware) many times trying with an app and with the micro SD card. My device will not connect. I have tried a Samsung Tablet, a Samsung cell phone, an IPad, and an IPhone. The IPhone does something but it only recognizes a different piece of equipment, not the Phantom 3 Professional - the Phantom 3 Professional panel just gives me a Learn how to Connect message, no Camera. I have contacted DJI online support at least four times and, although they try to help, they do not have great product knowledge and always end up telling me to send it to a service facility. I have tried to contact that facility and they do not respond either by phone or by email. I have tried 4 different USB cables and downloaded the app to all of the above devices at least three times each in case it was a app issue. I paid $2500 (plus the second camera) for this thing and all the advice I get is to send it in and pay more to get it working. Oh, and yes, I have tried every combination of C1 + C2 + Photo +Camera Settings buttons many, many times. I have tried direct connections from the aircraft to the RC and I have tried the relink button numerous times as well. I have chased this "dream" far enough and I am not spending any more money on something that is as fragile is this piece of junk so it will be put away and probably taken to the dump sooner or later. The only reason I am bothering to write this is that I am hoping that someone from DJI will read it and understand that they have made an enemy of me. I could have had more fun with a Walmart $300 toy and although I enjoyed the challenge of trying to get it going, in the end it is nothing but junk and DJI are simply bandits that only care about the next sale. Well, You alienated a customer and I know it doesn't matter all that much to you because there is another ten customers coming behind me, but you should consider the ten people I am going to tell about my experience and the ten people they will tell, and when you fade into black - and you will with junk like this - the quiet chuckling you hear in the background will be those of you abandoned in your greed.

Hi there, we apologize for the difficulties with the drone, the aircraft's firmware can only be updated via the Micro SD card, if the RC's firmware is higher than V1.3.2, it must be updated via the APP.
Since your mobile phone is unable to connect to the RC, we are unable to verify the current firmware version. It could be the unmatched firmware caused linking failure.
It is recommended to send in the RC and aircraft for the diagnosis, our repair center will help you out. I didn't see the email record via your Forum account, please send email to support@dji.com to start a ticket and send back, thank you.

Thanks for your reply DJI Mindy. Tried repair shops but they do not return emails or phone calls. Pretty useless if you ask me. Tried support@dji.com and their answer is basically send it in and maybe we will fix it and maybe it will work but make sure to send money anyway and we can't tell you how much until you send it in. Absolutely no point in spending any more money on your failed experiment and on any other DJI product for that matter. The unit will be scrapped and the lesson learned and after all, it is not the most expensive lesson I have learned anyway.