I'm a novice when it comes to this stuff. Basically, I wired up the lightbridge 2 onto a DJI S1000 (octocopter) that is using the A3 flight controller system. When I try to connect the LB2 Air System to the Ground System they both indicate that they are searching for a connection/trying to connect but eventually the DJI Go app indicates the connecting mode times before they actually link up. The LB2 Air System CTRL LED maintains a blinking red pattern the whole time ("Link button pressed. Air System is attempting to link with the Ground System.") and the Ground System/Remote Control has a blinking blue LED pattern ("Ground System is set as Master and is attempting to connect to the Air System"). However, they never connect. I'm not sure what the issue is.
My setup:
The A3 flight controller is connected to the LB2 via the RF port on the A3 to the DBUS port on the LB2. I do not have a gimbal, but I am using the gimbal port on the LB2 to power the system by using a step down voltage regulator to convert the main battery's 22V to 12V so that the LB2 doesn't get fried. I checked the voltages and they all seem to be at a good level. The LB2 is turning on properly, as is the A3.

Does anyone have any idea what the problem might be or know how it could be solved? Thanks for the help!

Minor edit: Before I try connecting the air system and ground system with the DJI GO app, if both are turned on then the air system will blink red with an occasional green blink thrown in there on the CTRL indicator. Not sure why.

you need to check the firmware of your air and ground unit, if the version is not match to each other,  they can not be paired.

Has anyone solved this yet?

Has this been solved. I am having the same issue.

It's an old thread but I encountered the problem today so here is the solution.
When the RC and the AC do not connect, there is a firmware mismatch. I updated the firmware on the Lightbridge 2 of my Matrice 600 Pro and could not connect anymore. I also updated the RC and then I, of course, lost track of what I had updated, which versions, and so on.

I made it all work again by having v1.1.81 firmware on the LightBridge 2 Air System and v1.2.52 on the Remote Controller.

And now I will tell you a secret that DJI does not tell you:
Using your Android or iOS device, you can roll back the firmware of your remote controller.

Launch the DJI GO app without having your phone or tablet connected to the RC. Right after the splash screen, in the screen where you choose an aircraft, there is a hamburger menu icon in the top right corner. Tap and hold this icon for three seconds, release and a black screen pops up that allows you to pick a firmware version and install it on your RC. It take 10 - 15 minutes, do wait until the process has completed.

See my screen shots.

youzq Posted at 2017-3-31 18:17
you need to check the firmware of your air and ground unit, if the version is not match to each other,  they can not be paired.

I matched them and it did not work. Only when I had version 1.2.52 on the ground and 1.1.81 in the air, things started to work again.