GPS Module issue?

[Finase]

Hi there,

I am having an issue with my DJI Mavic Pro and I wanted to see if anyone can help me with it. I recently accidentally flew into a tree and the propellers got chewed up. It was out of control and the remote controller was telling me "SYS WARNING / CHECK APP". I hit the Return to Home button and it came back over me but didn't come down, so I brought it over to a roof near me and tried to drop it there, it fell upside down (from about 3-4 feet) and on a tad bit of liquid/oil/mud type deal. When I got it, it wasn't very wet, just mainly dirty and scratched up. I went to clean it up. I replaced the propellers and calibrated the IMU, Compass, and sensors.

Now when I went to fly it, it would normally flash green and say "READY TO GO (GPS)". However, when I took off, it would go into "VISION (GPS)" and it would throw warnings saying something as to the effect of "GPS encounters data exceptions,please ask technical assistance for help" or "GPS entounters disconnect in flight". The drone's position doesn't update on the app and shows it to be where it took off from. I can't hit the RTH button either. The drone now has a steady red light and the controller says "SYS WARNING / CHECK APP". I still have control over it and can fly it, but sometimes it drifts away at altitudes of 40+ ft(with the wind maybe?).

Has this ever happened to anyone or does anyone have any suggestions to fix this? Any help would be GREATLY appreciated.

Thanks!

 

[Afremont]

Try recalbrating the compass again with no metal around you, including wearing a watch. Have someone else hold the controller while you do it.

 

[Finase]

I just tried that and it doesn't make a difference.

 

[Afremont]

I suppose it's possible that the GPS plug has unseated, or you didn't get it pushed all the way on when reassembling the Mavic. Take the shell apart again and check to make sure the connector wiring looks okay and reseat it.

 

[Afremont]

I suppose it's possible that the GPS plug has unseated, or you didn't get it pushed all the way on when reassembling the Mavic. Take the shell apart again and check to make sure the connector wiring looks okay and reseat it.

Maybe thunderdrones will have something to add; he knows a lot more about these things than I ever will.

 

[Finase]

Maybe thunderdrones will have something to add; he knows a lot more about these things than I ever will.

How do I find thunderdrones?

 

[Former Member]

How do I find thunderdrones?

Youve found him

OP, how many satellites are you getting on your controller? I think what @Afremont has said might be the case. If you are not getting any satellites, or if it keeps switching between Atti and GPS mode, your internal GPS module might have gotten damaged.

 

[Finase]

Youve found him

OP, how many satellites are you getting on your controller? I think what @Afremont has said might be the case. If you are not getting any satellites, or if it keeps switching between Atti and GPS mode, your internal GPS module might have gotten damaged.

I tried in my backyard just now and I was getting about 6-7 satellites. When I turned on the motors, all the satellites connections dropped and then I turned it off and the satellites came back. Turned on the motors a second time and they disappeared, so I turned it off again. At that point, the satellites still didn't show and I was just getting the GPS data exception error and it would not take off.

 

[AnzacJack]

Sounds like a simple loose connection.
Fingers crossed for you

 

[Finase]

Sounds like a simple loose connection.
Fingers crossed for you

Thats what I was thinking and quite frankly what I was hoping for.

I don't have any tools to open the drone so I took it to a local electronics repair dude and he called me within an hour. He told me I needed to buy a new GPS module although when I went back to get the drone, it had the same controller battery and four steady lights on the drone battery as if it had not been drained whatsoever. I asked the guy if the module had shattered or something and he didn't give me a response and just said, "regardless, it needs to be replaced".

 

[Rnl]

Only a few screws,go buy a set and check yourself, not hard at all.

 

[Finase]

Only a few screws,go buy a set and check yourself, not hard at all.

Do you know what are the type and measurements of screwdrivers I need to open it up?

 

[yachtsman]

they are small hexagonal type drivers. if the local diystore doesn't have anything go to a mobile phone shop as they have similar screws..

e bay is a good source as well..

when you open it up check the wires to the motors are still glued down and the ferrite ring is still round the wire to the GPS unit which is in the lid portion at the back above the red yellow green flashing leds.

GPS are very sucestable to interference and esc motors give off a a fair bit

 

[Finase]

I had the module replaced by a tech today with one I purchased on eBay. When I tried turning it on, I re-calibrated the compass but I was getting the same GPS disconnect error. This time, the GPS errors out completely, unlike the previous one I first started having issues with. As I mentioned above, the module that got swapped out was functional when I turned on the drone but it would start having problems when I turned on the motors or lifted off. This "new" module doesn't pick up any satellites at all and doesn't let me take off the drone at all.

Could the tech have improperly mounted the GPS module? Maybe there's a particular way you have to mount it for it to work?

Any thoughts?

 

[Afremont]

I had the module replaced by a tech today with one I purchased on eBay. When I tried turning it on, I re-calibrated the compass but I was getting the same GPS disconnect error. This time, the GPS errors out completely, unlike the previous one I first started having issues with. As I mentioned above, the module that got swapped out was functional when I turned on the drone but it would start having problems when I turned on the motors or lifted off. This "new" module doesn't pick up any satellites at all and doesn't let me take off the drone at all.

Could the tech have improperly mounted the GPS module? Maybe there's a particular way you have to mount it for it to work?

Any thoughts?

Did he use a DJI replacement part?

 

[Finase]

Did he use a DJI replacement part?

I purchased it, and I believe so... although I didn't order it directly from them.

This is the eBay listen for the part: Original DJI Mavic Pro GPS Module Board For DJI Mavic Pro | eBay

As it says: "100% original DJI
Original Authentic DJI Mavic Pro GPS Module Board as pictured.
This part is brand new removed from a disassembled new Mavic unit so it is a confirmed genuine OEM authentic
DJI part. All Mavic drones are bench tested prior to disassembly, we carry all parts for the Mavic and are
available by viewing our other items.
Compatible model：For DJI Mavic Pro"

 

[Afremont]

I purchased it, and I believe so... although I didn't order it directly from them.

This is the eBay listen for the part: Original DJI Mavic Pro GPS Module Board For DJI Mavic Pro | eBay

As it says: "100% original DJI
Original Authentic DJI Mavic Pro GPS Module Board as pictured.
This part is brand new removed from a disassembled new Mavic unit so it is a confirmed genuine OEM authentic
DJI part. All Mavic drones are bench tested prior to disassembly, we carry all parts for the Mavic and are
available by viewing our other items.
Compatible model：For DJI Mavic Pro"

This is a guess, but I'm thinking a mechanical problem with the receiving connector on the board in the Mavic. Pulling it off and pushing the new one on could have turned an intermittent connection into one that doesn't work at all. Like maybe a cold solder joint or even a cracked or broken circuit trace. Switching it back to the original module might verify that theory if it now has the same issue of not working at all. I'm just guessing based on general electronics experience, not Mavic Pro electronics experience. Honestly, I think the tech should have put a scope on the signal lines to check for something like that before deciding it just needs a new module.

 

[Finase]

Youve found him

OP, how many satellites are you getting on your controller? I think what @Afremont has said might be the case. If you are not getting any satellites, or if it keeps switching between Atti and GPS mode, your internal GPS module might have gotten damaged.

The techs I took this to weren't able to fix this for me, pretty useless overall they were if you ask me.

Do you do these kinds of repairs and if so is there some form or something to fill out somewhere to get started?

 

[Former Member]

The techs I took this to weren't able to fix this for me, pretty useless overall they were if you ask me.

Do you do these kinds of repairs and if so is there some form or something to fill out somewhere to get started?

Yes I do these types of repairs, I fix Mavics every day. I would also do a long range test flight to make sure the component is working before I sent it back to you.

Here is a link to my repair thread:

Thunderdrones Repair Information

 

[djwgates]

Did he use a DJI replacement part?

I had a similar issue. I replaced the board and nearly had a fly away. My fix was to downgrade the firmware in DJI Assistant 2 and upgrade it again. This way the firmware on the module and main board match. No issues what so ever since then.