Issue:
Okay so upon updateing many of the normal lightbridge 2 remote controllers as well as M600 black version, sometimes a failed firmware update results in the RC continuisly   beeping continuously (not due to stick calibration error) and gives other errors, it gives you the uption to update again but no matter how many times you do this it just loops the same issue,
I leared I can access a hidden menu within DJI go before p4 version of the app main menu tap and hold the three bars in the upper righthand cornor for about 8 seconds and downgrade menu will apear with the equiptment type and firmwars to chose from, mine says Inspire1 RC instead of Lightbridge 2, thus the firmware downgrade options are all inspire1.

How to fix:
Downgrading to Inspire 1.300 when you restart the controller after you will find it does not continuously beep again not due to stick calibration error, now its time to update normaly via the top banner to 1.7.8 inspire 1 firmware once this finishes, restart the controller to find it now back in lightbridge 2 equiptment mode, and under the the bars back door menu it says that and the current version is 1.1.0+  now going back in the camera view and selecting the top banner to update normaly, I update to 1.2.52 it failed at 8% but without restarting anything I taped try again and it worked this time. and now eveything is back working good!

Other tricks you can do to fix none detected RC's :
I dicovered you can press every button and wheel and power on the RC which would result in a white light when powered on, this is great for when the mobile device does not detect the RC and will allow you to connect update fimware ect.

when LB2 RC is in and working normal never press and hold C1 and C2 for many seconds because when you start getting a flashing light on the RC and reboot, this is when you can expect it not to conect to mobile device. from what I remember.


Also using IOS mobile tablet allows downgrading 100% of the time, although.  some android devices work to just not as many.

Hello there. Good day and thank you for sharing these interesting information with us. Again, thank you for your support and have nice day.