Video Feed failure

[MarkwH]

I took delivery of my Mavic Pro on Thursday 22/12/16. I've flown six times and on every flight I've lost the video feed within 90s or so. System recognises failure and offers RTH. App continues to operate despite no camera feed and Controller remains in control of aircraft. I've been online with DJI who advise recalibrate IMU and RC, reformat SD Card, download today's firmware update and relink controller. Nothing has worked. Even if I leave the aircraft stationary and connect everything up I lose the feed after a minute or two. Screen goes momentarily B&W and drops away. Controller unaffected. All other App data still there. I've read of similar problems with Inspire which were to do with faulty cameras? I've reinstalled the Go 4 app, and checked all cables are firmly attached. No joy. Any thoughts?

 

[chippie]

Why on earth do DJI immediately go in and calibrate the IMU.

OK, what device are you using? My first guess is that is is the cable (I had a similar issue with the lighting cable and heard of several others with the Micro-USB ones). Unplug the cable from the side of the controller completely, plug a different cable (one you know works) into the bottom port and power on. See if you still get the same issue.

Few other things, if on Android, Make sure USB Debugging is turned on under Developer Options. On iOS and Android turn off local caching in the app itself and select the option to automatically clear the cache down. See if these help.

 

[MarkwH]

IPhone 7plus. Will turn off local caching. I'll try the cable and let you know - I don't have another lightning to micro-USB so will get one. My gut feel is the cable except that I get the same failure when everything is on but not flying or touched - so no extraneous movement.

I suspect DJI support go through a standard check list before seeking to understand the actual issue.

 

[chippie]

No need to buy a new cable, use the cable you charge your phone with and plug it into the bottom port of the controller but you must remove the side cable completely before powering on. I had the same issue until the cable died completely. DJI replaced it and has been fine since.

Yes they do go though a standard list but calibrating the IMU should only be carried out under certain conditions, did they tell you to get the Mavic as cold as possible (kept it outside or even in the fridge) before doing so?...

 

[MarkwH]

OK - have done as you suggested and although I can't do a flight test (it is 21.15 here and pitch black outside) I have fired everything up and had a stable image on the screen for more than ten minutes - previously it disappeared within two. I didn't realize the USB socket could be used as an alternative to the micro-USB charging socket. I will flight test in the morning and update you however early indications from the bench test are positive. Have also changed the cache setting. Many thanks.

I am irritated to read what you say about the IMU calibration. I used DJI's online live chat support and initially communicated with 'Earth' who advised the recalibration. No mention of temperature but I followed the instruction on the app (five positions) and all appeared to work well. I would also say that when I got the Mavic Pro on Thursday (22.12.16 - seven week wait after paying DJI for it!) the controller and aircraft weren't linked and I had to do that manually. My two previous Phantoms were linked out of the box.

 

[chippie]

Unfortunately they just read dribble off a sheet in front of them.

OK, power the drone down and take the battery out. either put it in the fridge or outside if cold enough (not raining of course) Leave it there for a good 30mins to hour (do not forget about it lol) Get the controller and phone connected and go to the calibration screen, take the mavic out of the fridge, drop the battery in, power on and start the calibration as soon as it has connected. The main reason for doing this is that it can drastically reduce startup times especially when the outside temp. changes by a bit, not to mention making it more accurate.

With regards to the cache, just check your phones available storage and if there is enough then just re-enable it after a successful test with the cable, if the issue returns then it was probably down to the cache and so try the original cable again. If the cable, contact DJI support, explain and they should send you a replacement (remember not to calibrate the IMU again or listen to anything else they may offer) at this stage you have found the exact issue and just want a new cable.

Best of luck!

 

[Jaholibop]

Why on earth do DJI immediately go in and calibrate the IMU

A couple of stupid questions. What is the IMU and why is calibrating it such a big deal?
Thanks [emoji3]

 

[msinger]

IMU = Inertial Measurement Unit

If not calibrated properly, your Mavic might not be as stable when hovering in place.

 

[MarkwH]

Chippie: Have just completed two 20 minute flights without a hitch. Crystal clear sub zero conditions in the South West of England.

Your suggestion about using a different cable (and direct into the USB Port) was absolutely spot on. What worries me is: a. how a simple thing like a brand new cable can fail so badly, b. why DJI support appear to be unaware of this c. why I was asked to recalibrate the IMU, and the controller, format the SD card, relink the RC, download firmware etc. when a straightforward suggestion could have solved this immediately. DJI have also asked me to rebox and return the aircraft with the promise of a repair/replacement. This is a mission in itself with them asking for serial numbers of absolutely everything: craft, battery, RC and gimbal (where is the serial number on the gimbal by the way?). So many thanks to you for being so responsive and helpful.

Am now going to calibrate the IMU again following your previous recommendation.

 

[chippie]

I agree with everything you say. It really is unfortunate that they do not have great troubleshooting skills, perhaps had it no been so busy over Christmas things may have been different (I am assuming that they may have had extra staff in to help with the huge number of calls they received) although I have seen this a few times before, in fact I think it was exactly the same issue.

My advice, search or start a thread on here before contacting them

Oh and make sure you get that cable replaced. Have a blast flying!

@Blade Strike - Ken unfortunately another overzealous 1st line support person, perhaps you could bring it up again with the bosses