Mavic 2 ESC error

[paradanglers]

Hi all, I’ve recently bought a ‘spares and repairs’ Mavic 2 Zoom from MPB that has an issue with an ESC fault on all four motors. As far as I can tell the drone doesn’t appear to have suffered any water damage, all four motors look fine and when powering up they all give the usual couple of twitches as normal and there’s no smell of burning from the motors. The only other issues are that in the app there’s no battery info (no percentage, no individual cell voltage, no number of recharges or serial number) and the app states that battery voltage is only enough for RTH despite it being fully charged. Also there’s an intermittent ‘gimbal motor overload’ despite the camera working (seemingly) perfectly.

So far all I’ve done is to reflash the firmware which hasn’t cured anything. Can I ask if this sounds like an ESC board problem or possibly the ribbon cable connecting it to the main board? and is there any way to test it (or the motors for that matter) or is it just a case of buy a new one and hope fitting it solves the issue?

Thanks in advance.

 

[Starz]

There are a few connection terminals on the circuit boards inside the aircraft but without the diagnostic equipment probably in DJI’s possession it wouldn’t do us any good. Your”spares and repairs”unit seems to be just that, repair being the more pertinent part of the puzzle. You would need to open the unit and look to see if any previous repairs or replacement pieces have been added to the puzzle.
Post results if that’s in the mix.

 

[Cafguy]

It is a case of HOPE- Your problem Could be the ESC OR it could be almost anything. If you are really wanting to learn to repair with this drone then you need to open her up and carefully investigate each connection. If you are wanting to repair it yourself just to save a little money-You won't -Send it to DJI for repair.
I would start with a new Mainboard and work around that with each component.

 

[paradanglers]

Thanks Guys, I think I’m definitely going to have a go at replacing the ESC board, but I realise how big a money pit I could be entering in to if that doesn’t fix it, as you say Cafguy it could literally be anything (or possibly even everything!). The case doesn’t look like it’s been opened yet to investigate any problems so that will be my first job. If the ESC doesn’t fix the issue it may end up that it’s more ‘spares’ than ‘repairs’ but I reckon it’s got to be worth a try at least.

Thanks again for your time, and if I get anywhere with it I’ll be sure to let you know!

Kindest Regards.

 

[Starz]

If you look closely at the screw heads, there will be two I think that have a glue type plug in the top of the screw. If that material is gone, it’s probably been apart.

 

[Cafguy]

Thanks Guys, I think I’m definitely going to have a go at replacing the ESC board, but I realise how big a money pit I could be entering in to if that doesn’t fix it, as you say Cafguy it could literally be anything (or possibly even everything!). The case doesn’t look like it’s been opened yet to investigate any problems so that will be my first job. If the ESC doesn’t fix the issue it may end up that it’s more ‘spares’ than ‘repairs’ but I reckon it’s got to be worth a try at least.

Thanks again for your time, and if I get anywhere with it I’ll be sure to let you know!

Kindest Regards.

Go ahead and purchase all new ribbon cables there really is no inspecting them So I would spend the money and eliminate that right out of the box. As Starz says if the Epoxy is missing from the screwheads of the drone someone has been inside. ESC are not all that expensive and easy to get let us know how it goes. If the drone was in a crash you may simply have a bunch of dislodged connections.

 

[paradanglers]

Funny you should say that Starz, there was a screw holding on the small plastic cover underneath the front arm that still had glue in it exactly as your picture shows, so I guess no one has attempted to fix it yet. This afternoon I managed to get the cover off and just lifted the ESC board up to have a look without de-soldering anything, doesn't look like anything has burned out on it but after putting everything back it's still giving the same errors.

Buying a new set of ribbon cables is a smart move, thanks Cafguy, they're pretty cheap and it would be a shame to change everything and still have it not work just because one of the connections was faulty.

At the minute I'm curious to see if a new ESC board would cure the battery percentage problem as it seems like all the issues could be coming from the same PCB (or its connectors).

The only outward signs of the drone having a crash is that both front leg struts (I think they house the antennas) have been bent back but they don't look the sturdiest of designs so I guess this might be a common problem with them?

My next step is to order the ESC board and ribbon cables, so prob a week or so before I get any more progress on it.

Thanks again guys, your help is much appreciated!

 

[Starz]

Unless you see some form of damage in these cables or some drastic kinks, I would skip the ribbon cable idea. Any deformity seen on the metal covers on the boards?

 

[paradanglers]

So far Starz everything on the inside of it looks absolutely pristine, which is now making me wonder whether the faults could actually be caused by a duff battery rather than the drone itself, It's the longest of long shots I know but it seems like all the issues (ESC on all four motors plus the gimbal overload) could possibly be down to a power delivery problem. I realise power delivery is basically the job of the ESC board, but combined with the drone faults and the app being unable to see the battery percentage or serial number etc is making me think it could be the battery. I've ordered a 2nd hand battery to try as I've currently only got the one that came with the drone, and I guess a back up will come in handy when I finally do get it all working. The battery should be turning up Thursday. Keeping my fingers crossed till then!

 

[paradanglers]

Well I said it was a long shot and it was . The drone is having the exact same issues with the 'new' battery as with the old one, so it's back to the ESC board as the most likely culprit for all the problems, got a new one on order now but it's probably going to be nearer the end of the month before I get chance to fit it.
Thanks again for your help guys and hopefully I'll have some better news in a few weeks!

 

[paradanglers]

Little update, while I had time this weekend I thought I'd start stripping the drone down ready for the new ESC board and found this. It's the ribbon cable that goes from the ESC to the Core board and there's a tiny tear right in the corner. I cant 100% rule out he possibility that I've done it myself when stripping it down, but I don't think I was overly rough with removing the connector. Anyway I've also ordered a new ribbon now which I'll try before putting the new ESC Board in.

 

[paradanglers]

Well it turns out all it needed was the ribbon cable after all, my replacement ESC board is now a handy spare just in case I ever do need one. The drone flies great now but I'm still having the problem of the 'gimbal motor overload', turns out the motor controlling the roll of the camera isn't working so as I turn the drone the horizon line doesn't stay flat. It's not going to affect me taking photos with the drone but any videos I take that aren't in a straight line are going to look a bit funny. Thanks again for your help and time guys & Happy Flying!