Hello, Please if you can, avoid answers like "you should return your drone for assistance", that's what I'm trying to do, with a lot of obstacles I explained in another post..
So, in the meantime, I'm trying to understand exactly what the trouble is...
I crashed it, I broke the glass in front of the ginbal, but the lens is still free, so the image is still good
I also broke the cap under the front "black"  motor,  the small round PCB now is exposed, but nothing looks broken...
Almost verything is fine, the drone flies fine, THE "RADAR" on the DJI go 4 app indicates the right direction, as I rotate the drone it changes the right way, so the compass seems to be OK!
If I try to calibrate, I can pass successfully from the "yellow LED's" phase to the "green LED's" phase, but the next phase ends with  an error... it says there is too much magnetic interference...
I did recalibrater Gimbal, IMU,  re-installed the firmware, but no luck...
My impression is something "silly" has happened, something that I could even afford to fix myself.(I work in an Electronics company).. but first I should know where are the compass(es) located and how can I inspect them...
In any case I'm curious to know how can it be possible that the compass seems to be operating correctly and yet the calibration fails because of interferences..
Again, Please don't tell me anything like "please send you spark back to DJI", i'm DISGUSTED about what's happening to me in terms of DJI Customer care, so I'll do my best to avoid this..  period...
Thanks a lot to anybody who will give me some technical clarification....

Try to calibrate outside and away from electronics and buildings and such.
Sounds like your bird took a beating, the motor cap can be replaced - check eBay.
Not too sure about the lens cover.
Honestly I would send it in for repair if you can live without the drone for 2 weeks - well worth it, after all you never know if something else might be damaged that isn't so obvious on the first glance.

Even wifi signal from your router can cause interference with compass. So compass calibration should be done outside far away from house, buildings atleast 50 m. and put your mobile in airplane mode. The compass unit is located at the back part where you see DJI logo. But I do not think you can do anything with it because it is electronic compass, an IC. If you want to tear Spark down, search Youtube "Dji Spark Teardown", you can do it with iFixit tools. I am sure that you will endup with brand new Spark. Choose faverite color.

The Spark's compass is on the head of the drone. If the app said magnetic interference, you can try another place to calibrate, don't leave it on the ground after powering it on. But may I know why you don't want to ship the drone back, is there anything happened before? I am terribly  sorry for our service hadn't met your needs. But since the drone was crashed, I would really suggest sending it in for repair for your flight safety and the drone's warranty maintenance. Hope your kind understanding.

This is inside Spark. Front is at the right. GPS is in the back , left side.

I don’t think DJI would put compass at the front. There are fan motor and gimbal motor there and could confuse compass.

DJI Thor Posted at 2017-9-19 21:36
But may I know why you don't want to ship the drone back, is there anything happened before? I am terribly  sorry for our service hadn't met your needs.

@dji Thor , I Think I had been even too clear and tedious in explaining what happened in other posts...  I briefly repeat the story once again..  I did buy  the DJI Care Refresh, together with the Flymore combo,  the drone came to me on mid june, the shipping note said that the Care Fefresh should "come later"..
Now I need to send it back, but after 4 months the serial 0ASDE5D0A100MN has still NO CARE REFRESH BOUND TO IT, i've sent a ton of mails to dji support,  [url=mailtonlinesales@dji.com]onlinesales@dji.com[/url] and djicare@dji.com.. I asked for help in this forum, I coped / pasted many time the mail with the shipping note, I also  attached a picture of the "belly" of the drone with its serial..  
From time to time someone replies to my mails with "oh, we are so sorry, we have forwarded you data to the righe department, please be patient"....  
Well, my patience is over now... half an hour ago I checked again for coverage and it still not covered..  I'm going to attempt a legal action against DJI if things do not settle down within this week...
Excuse me for being so rude, but I use Spark for work, not for fun.... and I'm loosing a lot of potential.. jobs..  the accident to the aircraft is my fault, it's true, buT AGREEMENTS ARE AGREEMENTS, period

DJI Thor Posted at 2017-9-19 21:36
The Spark's compass is on the head of the drone. If the app said magnetic interference, you can try another place to calibrate, don't leave it on the ground after powering it on. But may I know why you don't want to ship the drone back, is there anything happened before? I am terribly  sorry for our service hadn't met your needs. But since the drone was crashed, I would really suggest sending it in for repair for your flight safety and the drone's warranty maintenance. Hope your kind understanding.

No, it's not depending on where and how I calibrate, never had a calibration fault before the crash, after the crash there is no way to calibrate, wherever i do it,,,

Let's speak technical now, if I go to the DJI Go 4 app, setting ->  sensors > compass, there is a numeric value and an horizontal bar....  even with the drone solid stopped on a flat surface, far away from any magnetic field, the numeric value is "waving"  continuously...  as well as the bar, that keeps becoming longer and shorter, changing color from green to yellow, and sometimes red.... it's as if some magnetic field around was continuously changing its strenth, but the drone is still solid and there is no magnetic field in the neiborhood....

la_panza Posted at 2017-9-19 22:38
@dji Thor , I Think I had been even too clear and tedious in explaining what happened in other posts...  I briefly repeat the story once again..  I did buy  the DJI Care Refresh, together with the Flymore combo,  the drone came to me on mid june, the shipping note said that the Care Fefresh should "come later"..
Now I need to send it back, but after 4 months the serial 0ASDE5D0A100MN has still NO CARE REFRESH BOUND TO IT, i've sent a ton of mails to dji support,  onlinesales@dji.com and djicare@dji.com.. I asked for help in this forum, I coped / pasted many time the mail with the shipping note, I also  attached a picture of the "belly" of the drone with its serial..  
From time to time someone replies to my mails with "oh, we are so sorry, we have forwarded you data to the righe department, please be patient"....  

Sorry for your case, I remember now and had replied you in another thread, please check. Thank you.

DJI Thor Posted at 2017-9-20 18:56
Sorry for your case, I remember now and had replied you in another thread, please check. Thank you.

Yes, everything's fine now..  Care refresh service agreement has been sent, I'll ship my aircraft tomorrow...  thanks a lot..

la_panza Posted at 2017-9-20 23:39
Yes, everything's fine now..  Care refresh service agreement has been sent, I'll ship my aircraft tomorrow...  thanks a lot..

You are welcome. Should you have any further questions, please feel free to contact us. We'd glad to help.

DJI Thor Posted at 2017-9-21 01:05
You are welcome. Should you have any further questions, please feel free to contact us. We'd glad to help.

Well...  now I have doubts about my shipment.
In the form I filled for the care refresh, I included the remote controller, because it has a problem in the female USB connector..  (not caused by my mistake.. I think...) it works but charging the battery is a hassle because of a broken contact...
Then, reading carefully the service agreement terms, I saw a point where they say "Do Not send back the remote controller".....
Now I've already filled the form... I still have to make the pagkage so I'm stil in time to decide whether I have to put the remote controller in.. what do you suggest?  In case I don't ship the remote controller, should I edit and modify the form?  How  can this be done?   Thanks

la_panza Posted at 2017-9-21 01:41
Well...  now I have doubts about my shipment.
In the form I filled for the care refresh, I included the remote controller, because it has a problem in the female USB connector..  (not caused by my mistake.. I think...) it works but charging the battery is a hassle because of a broken contact...
Then, reading carefully the service agreement terms, I saw a point where they say "Do Not send back the remote controller".....

Sorry for the late check, and I had received your PM and answered there. You can send the broken parts to us and we will take care of it for you. But please note that do not ship the excluded parts if one uses DJI Care Refresh Express.

DJI Thor Posted at 2017-9-26 23:59
Sorry for the late check, and I had received your PM and answered there. You can send the broken parts to us and we will take care of it for you. But please note that do not ship the excluded parts if one uses DJI Care Refresh Express.

Hello, unfortunately the package has arrived to DJI Europe yesterday and the remote controller was included in the package, I Know they received it just ftrom the UPS Tracking service, DJI did not send me any feedback yet..
Since I didn't have any reply to my PM  I decided to ship......  it's still not clear how things will go on now...  the drone was covered by the care refresh... but the battery and the RC were not,  will this cause a further delay to have the drone back?  I'm quite  worried about this...  after all I wasted one week for a problem that was not my fault... if the care refresh was active as expected I could ship on september 18th and probably the saga was already  closed today....  what can we do to avoid further delays?
Regards

la_panza Posted at 2017-9-27 01:44
Hello, unfortunately the package has arrived to DJI Europe yesterday and the remote controller was included in the package, I Know they received it just ftrom the UPS Tracking service, DJI did not send me any feedback yet..
Since I didn't have any reply to my PM  I decided to ship......  it's still not clear how things will go on now...  the drone was covered by the care refresh... but the battery and the RC were not,  will this cause a further delay to have the drone back?  I'm quite  worried about this...  after all I wasted one week for a problem that was not my fault... if the care refresh was active as expected I could ship on september 18th and probably the saga was already  closed today....  what can we do to avoid further delays?
Regards

Please provide me the case number, I can check the situation for you. Thanks for your support.

DJI Elektra Posted at 2017-9-27 01:54
Please provide me the case number, I can check the situation for you. Thanks for your support.

CAS-1021587-J2C7V1

As you probably know, there has  already been a one week delay because a problem on DJI site, DJI Care refresh was not activated 2 days after purchased as it should, , and it took  one week to fix the situation, so please, I hope my case will be handled with High priority, I don't have a backuop drone and I'm blocked with my work...  I don't care about the remote controller, I have another one...if the remote controller is something tha makes the thing  even longer, please ignore it and discard it...  I NEED  THE DRONE BACK URGENTLY...

Thanks for understanding...

la_panza Posted at 2017-9-27 03:37
CAS-1021587-J2C7V1

As you probably know, there has  already been a one week delay because a problem on DJI site, DJI Care refresh was not activated 2 days after purchased as it should, , and it took  one week to fix the situation, so please, I hope my case will be handled with High priority, I don't have a backuop drone and I'm blocked with my work...  I don't care about the remote controller, I have another one...if the remote controller is something tha makes the thing  even longer, please ignore it and discard it...  I NEED  THE DRONE BACK URGENTLY...

It showed that your package was signed on 26/9, it would take 3-5 business days to record it to our system and get an update. I had forwarded your needs to the designated time to speed up the process. I believe they will do something, hope you can get the drone back soon.

DJI Thor Posted at 2017-9-28 00:59
It showed that your package was signed on 26/9, it would take 3-5 business days to record it to our system and get an update. I had forwarded your needs to the designated time to speed up the process. O believe they will do something, hope you can get the drone back soon.

Thor, I can agree and understand it takes 3 to 5 business days as a standard procedure, but you also must agree my case is a peculiar anomalous case, I have no idea about how often DJI "forgets" to fulfill an agreement with one of his customers, in my case this has brought up to one week time shift, I wil repeat it to bear it in everybody's mind, so, the least I could expect was that semeone would be so kind to "override" the standard process and kept an eye to my precedence over the normal RMA flow.... but maybe I'm asking too much...   

la_panza Posted at 2017-9-27 03:37
CAS-1021587-J2C7V1

As you probably know, there has  already been a one week delay because a problem on DJI site, DJI Care refresh was not activated 2 days after purchased as it should, , and it took  one week to fix the situation, so please, I hope my case will be handled with High priority, I don't have a backuop drone and I'm blocked with my work...  I don't care about the remote controller, I have another one...if the remote controller is something tha makes the thing  even longer, please ignore it and discard it...  I NEED  THE DRONE BACK URGENTLY...

Ok, I received the ProForma Invoice on last Friday september the 29th, I paid the 49 Euro via Paypal thr same day...  what should happen now?

DJI Thor Posted at 2017-9-19 21:36
The Spark's compass is on the head of the drone. If the app said magnetic interference, you can try another place to calibrate, don't leave it on the ground after powering it on. But may I know why you don't want to ship the drone back, is there anything happened before? I am terribly  sorry for our service hadn't met your needs. But since the drone was crashed, I would really suggest sending it in for repair for your flight safety and the drone's warranty maintenance. Hope your kind understanding.

Compass locate at the head of drone, are u mean the 3D Sensor?

Onndee Posted at 12-16 03:52
Compass locate at the head of drone, are u mean the 3D Sensor?

Hello Onndee, may I know the reason you need to confirm the location? The compass is not on the 3D sensor. Thank you for your attention.

The compass is the metal box directly behind the infrared modules of the 3d sensor.  If it goes in water it becomes magnetized. Replace the 3d module if firmware down grade upgrade doesn't solve compass errors.

Onndee Posted at 2018-12-16 03:52
Compass locate at the head of drone, are u mean the 3D Sensor?

Yes. The 3d sensor has the compass on it in a spark.

djiuser_WgfjGw7qMKWW Posted at 7-2 16:19
Yes. The 3d sensor has the compass on it in a spark.

I believe the compass is integrated into the IMU which is the little box like thing attached to the gimbal mount.

Compass is in the front sensor behind what would be front left corner. For sure

simple , go to another area and calibrate your Spark .