I decide to update the fiirmware today, and it happend something I never expect and never saw on the forum neither. the very loud D--D--D--D not the normal small noise D-D-D-D  (watch the video)happed during updating.then I link to my RC to see what's in the information status, it gives me list of errors. so weird, I double check everything again, and re upgrade one more time, the loud D--D--D--D still going, but I insist to wait about 20 mins, it stopped and everything going back to normal upgrading sound, and finally change to small noise to D-DDD. so I checked the tx file, it says upgrade success. I wonder has anyone get this wired experience before? I upgrade RC in 5 mins. I have not check the status when I am posing this thread, I will follow up with it though. I feels like my Bird got serious hardware problem when I hear the wird loud D sound, remember it got crashed before, I sent back to DJI and it got fixed.

All my updates has been succesfull so far and I never heard that sound ...

Nope, never heard anything like that from my Inspire during an update.   Sounds kind of pained.

Any DJI people here can explain what's going on here?

That's news to me as well - all my updates have gone on more or less without a hitch.

thats just the ultrasonic sound...

freddiebd@iclou Posted at 2015-5-17 14:38
thats just the ultrasonic sound...

Not the overtones, what does it mean when it just slow-beeps like that?

That sounded like the on-board speaker was relaying RF interference from an unsuppressed ignition system on an engine. The slow regular beep sounded like an error warning.