I have been having a big problem with my DJI Mavic Mini. My drone has been working perfectly fine at home. The first problem happened about a year ago. I was trying to fly at my grandparents house. But for some reason the drone would not connect to the controller and my phone would not connect to the controller. I tried using my dad's phone, with no luck. It wasn’t a big deal that it wouldn’t work, so I did not contact DJI Support. About half a year later we bought a cabin. I was very exited to fly my drone, and get super cool shots. I was very disappointed when my drone would not connect to the controller and my phone would not connect to the controller. I restarted it and everything and it would simply not work. When I got back home, I contacted DJI Support via the DJI Fly app. They thought it was because of “severe interference”. I did not think that was true, because there are few buildings, no power lines, no strong internet sources or anything. I was EXTREMELY disappointed. About 3 months later, I was planing to fly it at my extended family’s house for a major photo shoot (about 50 people), and when I was counting on DJI most, it would not connect. While 50 people were waiting around 10 minutes, I finally got the controller to connect to the drone. The phone still would not connect, though. I tried to fly it without using my iPhone, but I could not see anything. After returning to the car and stopping at a gas station, it connected perfectly fine.  I have looked everywhere on the internet and I can’t find anyone else having this problem. I am contacting you to see if you can help. Thanks!

Look at the photo and video files on the drone's memory card, are any of them corrupt or inappropriately named (names not of the normal layout or with gaps in their name)?  The simple test is to switch the drone off, remove the card and then switch the drone on again.
I have the recollection that such a problem can prevent a connection being made between the drone and the controller (Mavic 2 Pro or Zoom ). There is, I think, some other 'stupid' thing that can cause the problem but I can't remember what it is and could be wrong.

With regards to the phone's connection to the controller, the suspicion falls on the cable or the connections at either end. Care in needed with micro USB connections and if you are using a non standard cable ESPECIALLY the connection on the controller. The controllers socket is a type A socket (rectangular) and it is possible to try to fit a type A or type B (Phone-connector) the wrong way up which could damage the socket. See

https://en.wikipedia.org/wiki/USB_hardware

Personally I use the cable sliders, from the likes of the Mavic 2 Pro, to hold the phone plug in place in the swing out arm. I find it makes connecting the cable to the phone an awful lot easier but those sliders are ridiculously expensive for what they are - unless you get lucky on ebay.

Besides which they are getting difficult to find.

If you are using a non standard cable then it may also require that the plug going into the controller is an OTG plug but other people will need to confirm or  refute that.

I use a somewhat different start-up sequence than what's recommended in the DJI Tips, but it's always worked for my Mini-1:

1) Make sure all components are fully charged.
2) Close all running apps on your phone/device, and then open ONLY DJI Fly. Phone memory in use by other apps can cause the phone not to link.
3) Plug the phone into the RC with DJI Fly running, but the RC OFF.
3) Turn on the aircraft.
4) Turn on the RC.
5) On the Mini-1, the synchronization start-up dance can take a while. Give it time. Allow up to 5 minutes if you haven't flown the aircraft in a while.
6) If that doesn't work, run the "Connection Guide" that appears in the lower right of the DJI Fly home screen. If it doesn't work, it may give you an indication why not.
7) If you're not using and Android device, YMMV. I don['t know from iOS!

Good luck, and please let me know if this works.

TCS

Hello there MavicMiniFlyer. I am sorry for the trouble this has caused and thank you for reaching out. May we please know what is the model of the mobile device that you are using please and are you receiving any error message or error codes on the DJI Fly application when this is happening? Thank you.  

DJI Stephen Posted at 8-7 19:25
Hello there MavicMiniFlyer. I am sorry for the trouble this has caused and thank you for reaching out. May we please know what is the model of the mobile device that you are using please and are you receiving any error message or error codes on the DJI Fly application when this is happening? Thank you.

I used both a iPhone 8 and a iPhone SE Second generation. I am not receiving any error it just says “RC Not Connected”

and did you try the suggestions made in post 2?

Sean-bumble-bee Posted at 8-7 12:43
Look at the photo and video files on the drone's memory card, are any of them corrupt or inappropriately named (names not of the normal layout or with gaps in their name)?  The simple test is to switch the drone off, remove the card and then switch the drone on again.
I have the recollection that such a problem can prevent a connection being made between the drone and the controller (Mavic 2 Pro or Zoom ). There is, I think, some other 'stupid' thing that can cause the problem but I can't remember what it is and could be wrong.

Thanks for the information. Now the drone is connecting to the controller, but the phone still won’t connect to the phone. I am using the cable that came with the drone, so I think that is the problem. The cable is a few years old and might now work anymore. Do you think that could be a problem? I don’t want to spend $24 for a new cable and that doesn’t fix the problem. Thanks!

Chaosrider Posted at 8-7 14:48
I use a somewhat different start-up sequence than what's recommended in the DJI Tips, but it's always worked for my Mini-1:

1) Make sure all components are fully charged.

I followed you exact directions and it didn’t work. I think the cable connecting the phone and the controller is not working. Do you think a new cable would fix it?

MavicMiniFlyer Posted at 8-8 07:14
I followed you exact directions and it didn’t work. I think the cable connecting the phone and the controller is not working. Do you think a new cable would fix it?

I can't think of anything else to try.

I'd definitely contact DJI Support, if you haven't already.

Good luck!

TCS

MavicMiniFlyer Posted at 8-8 07:11
Thanks for the information. Now the drone is connecting to the controller, but the phone still won’t connect to the phone. I am using the cable that came with the drone, so I think that is the problem. The cable is a few years old and might now work anymore. Do you think that could be a problem? I don’t want to spend $24 for a new cable and that doesn’t fix the problem. Thanks!

Before buying a new cable check whether or not the phones connects to a computer via USB cable, if not check the USB settings on the phones. I am not familiar with iPhones so can't remember if that is an applicable concern. Also check whether or not they are easily charged via cable, i.e check the phones' sockets.
I assume you are using the micro USB  to iPhone lightning cable, is that correct?
Do you have the two other controller to phone cables that came with the drone? USB-C and micro USB phone connectors.
If so, do you have a USB-C-female-to-Lightning-male adapter or a micro-USB-female-to-Lightning-male adapter that you could connect to one of those two cables and then connect the adapted cable to your phone.
I am not certain that such a test will work BUT if your phone does connect whilst using such an arrangement then it would suggest that the original cable is at fault.
Alternatively, do you have access to a fly app compatible Android phone? With the appropriate cable that would test whether or not the controller's socket is okay.
To be honest I would be a bit surprised if the cable is at fault but my cable probably has an 'easy life' due to my using the sliders I mentioned. I recollect that without the slider the cable has to be handled rather a lot to fit connect it to the phone.
That said I would look in ebay for second hand cable ( there's may be a reasonable chance of picking up an unused second hand cable) before shelling out $24 for one.

Chaosrider Posted at 8-8 08:17
I can't think of anything else to try.

I'd definitely contact DJI Support, if you haven't already.

contacted DJI support. they said an engineer will email me within two business days.