Here is a copy of my post from a different forum. I'm getting no relies there, may be someone will help me here.

So, I received a new Mavic, got it out of the box and remote was always in "connecting" mode. I tried to plug in my iPhone but it didn't see the remote either.

That was the first time it happened and that's how I fixed it:
1. Connected RC to my Mac and Launched DJI Assistant 2 app.
2. Downgraded firmware to 03.0400 and it succeeded.
3. Upgraded to 03.0500 and it failed.
4. Repeated steps 2&3 around 5-7 times, and then it finally succeeded. I'm not sure what changed during the process.
5. Upgraded to 03.0550 and was good to go.

Then, few days later 03.0600 came out. I upgraded with DJI Go app on my iPhone and it succeeded. I used my drone for a week after that.

Then, I started my trip to Ecuador and just when I arrived here I noticed that my RC is again in this weird "connecting" mode. It doesn't connect to the drone, doesn't connect to my iPhone, doesn't enter the pairing mode through C1 and C2 and shutter buttons. On the other side the remote DOES charge my iPhone (when it's working normally, it doesn't charge it). Drone is still working over wi-fi connection, though.
So I fire up DJI Assistant on my Mac again, it takes 5 hours to download 03.600 firmware over crappy wi-fi. I'm able to just "Refreshe" it and it succeeds from the first try. So I'm good to go... but only for 2 days.

So, 2 days later I get my remote out of the bag, and holy glory, here we go again, this bloody glitch is back. Remote is AGAIN in "connecting" mode. I come back home hoping to revive it through DJI Assistant app on my Mac, but this time it doesn't work. No matter what firmware I choose (I tried, 03.0400, 03.0550, 03.0600), it always fails the update/downgrade, always at 20%. Sometimes the app warns me that there are "inconsistencies in remote modules", and offers me to fix the issue by updating the firmware. If I agree it successfully goes up to 100%, and firmware seems to be updated, but it doesn't fix the glitch. I tried changing USB cables and usb ports on my mac, but nothing helps.

All right, after 2 days of worthless attempts to revive my RC, I stumbled upon Assistant app logs. I noticed that internal RC firmware consist of 3 parts, and here is how they load up:
"Remote_radio (6 :0) device no reply, request timeout!
Dm368_ground (13:1) Ldr : 1.5.0.20 App : 1.5.0.20  
Ofdm_ground (14:7) Ldr : 0.0.0.0 App : 47.26.2.8 "

So, looks like "Remote_radio" is not loading up properly.

I tried to wait, and presto, after around 5 minutes this module started to work and here is the output I've got:
"Remote_radio (6 :0) Ldr : 8.0.0.9 App : 0.0.1.27  
Dm368_ground (13:1) Ldr : 1.5.0.20 App : 1.5.0.20  
Ofdm_ground (14:7) Ldr : 0.0.0.0 App : 47.26.2.8 "

I tried to upgrade to 03.0600 firmware at this point and it successfully finished! After this upgrade the RC is now able to connect to my iPhone and I can see it's firmware version in DJI go app (but serial number is hidden). I can calibrate remote too. The iPhone is not charging from remote anymore.

Unfortunately it's still in "connecting" mode. I'm trying to activate binding, but it doesn't work, neither through the app, nor through C1+C2+Record++Shutter button combination.

Well, checking what else I can do... If anyone can help, I would really appreciate that!

When you are trying to bind the RC to the Mavic, make sure the Mavic is set to RC not wifi.
Then follow the instructions in the manual:

1. Turn on the remote controller and connect to the mobile device, and turn on the aircraft. Launch the
DJI GO 4 app.
2. Enter the App settings and  tap the “Linking Primary RC” or “Linking Secondary
RC” button to confirm.
Toggle the Control Mode switch to RC mode before linking.
3. The remote controller is ready to link.
4. Locate the linking button on the side of the aircraft, as shown in the figure below. Press the link button to start linking. The Linking Status Indicator will display a solid green once the remote controller is successfully linked to the aircraft, and the LCD screen on the remote controller will display the aircraft’s information.

Failing that, contact DJI support.

You might use assistant 2 to update RC then AC separate.
connect AC(only) to computer and update it then connect RC (only) and update it

Jenee 2 Posted at 2017-4-20 20:50
When you are trying to bind the RC to the Mavic, make sure the Mavic is set to RC not wifi.
Then follow the instructions in the manual:

Hi, thanks for the reply.

As I stated in my original post, RC is not entering the "Binding" mode, not through the app, nor through the button combination. Both ways nothing happens (the DJI go doesn't even let me choose primary/secondary controller, the window just closes as soon as I click the button)

hungdang Posted at 2017-4-20 21:03
You might use assistant 2 to update RC then AC separate.
connect AC(only) to computer and update it then connect RC (only) and update it

Hi, I describe the procedure of what I tried to do to update it in my original post.

As you can see, the remote updates (with hissups, as described in the post), but doesn't bind to my mavic.