Video Problem after Repair HELP!

Dyno · May 4, 2018

I bought a crashed Mavic Pro. It flew fine but camera did not work. Seller said he took apart but over his head.
I took apart and found these problems. Broken gimbal cables both video and gimbal. Damages pc board where gimbal cable and video cable plug in, and ribbon cable for gimal control from thar pc board to main pc board. Would have only need video and gimbal cable, but previous owner damaged other parts with his fat fingers!
I ordered all parts from China and installed. This is the result.
This is what I get when when watching live view in phone too. I have tried 2 different cell phones, Galaxy S7 and LG V20. Have tried latest firmware drone and controller and tried downgrading firmware drone and controller. Have tried various video setting, nothing changes.
Any ideas?

Mad Mavic · May 6, 2018

Snoop around here and see if someone has a fix. Off the cuff it looks like issues from the stranded cable but firmware would be my first start.

o-gs/dji-firmware-tools

Dyno · May 6, 2018

Mad Mavic said:
Snoop around here and see if someone has a fix. Off the cuff it looks like issues from the stranded cable but firmware would be my first start.

o-gs/dji-firmware-tools

I should add that I have since tried a spare camera I had and a different stranded cable, none of which changed problem. Thanks for suggestion though, I will certainly pursue your suggestion. I think problem is with where ever video stream from camera is processed, but I don't know where that takes place. This is board I replaced:
Original For DJI Mavic Pro Drone RC Gimbal Camera Forward Sensor Control Board | eBay
I am not sure if this board does some video processing that may be causing problem or does it simply a transfer point that moves stream from stranded cable to one of the ribbon cables onto the large main pc board where stream is processed.

Mad Mavic · May 6, 2018

Did you play around with the HD setting in the GO-4 app? Switching from auto to custom allows you to slide the frequency window to the area of least noise. It would be interesting to know if that had any affect good or bad.

If I recall, the RC is on the 2.5GHz side and the video on 5.4 GHz

Dyno · May 6, 2018

Mad Mavic, Thanks for reply, went ahead and tried what you said, alas, no help, still the same effect in transmission, recorded video and stills. when taking still shots, if you catch it right, image perfect, other times a portion of still is purple.

FastHampster · Jul 28, 2018

Hi Dyno, did you fix your problem. i bought a used unit as well and it seems it has the same video issues regarding the pink / purple at times and other times no issues.

Dyno · Jul 29, 2018

I have had 3 mavic pro's. The first one I had had the described problem. For some problems, it seems no one really has the answer to the real cause of the issue. I went ahead and bought a good one so I would have complete assembly parts to change out to isolate the problem. Problem is worst case...main core board, the most expensive part it seems. No doubt the problem is in the video processing section, but no research I did found anyone or company that actually repairs boards. I'm in Canada, so best price on eBay is $175 USD. Close to $250 CDN by the time all conversions and taxes paid. I'm waiting in hopes of better price as Mavics become less popular.
Hey if you catch it right, you can still take nice pictures or pull frames from videos for pictures.

Dyno · Jul 29, 2018

My new problem is with one of my batteries now. "battery authentication failed" No one has answer for that either it seems. Battery now paper weight or expensive power bank! Battery fine...just can't fly!!

FastHampster · Aug 11, 2018

Hi Dyno, i just recieved a cable and started to dissemble the mavic. When i got the cover off i noticed that the video cable was pinched under the left side forward sensor. I re/re the sensor and removed part of the wire that was pinched. Reassembled and the video is working now with no purple lines. Flew it for 20 mins and nothing. Hopefully it stays like that

ChipZ_601 · Nov 11, 2018

I’m having the same issue. I crashed my Mav in a lake and it sat there for 6 weeks. I eventually got another Mav and used litchi to find it. It’s just a fun project now to bring it back to life. Finally got it all cleaned and back up and working. Needed a new main board ($170 on eBay) and replaced the camera lens sensor. But I have the purple flickering. Even on the SD card. I ordered new transmission cable and the other cables to the forward sensors. Should know in a few days if this fixes the problem. Any other advice would be appreciated.

Dyno · Nov 11, 2018

ChipZ_601 said:
I’m having the same issue. I crashed my Mav in a lake and it sat there for 6 weeks. I eventually got another Mav and used litchi to find it. It’s just a fun project now to bring it back to life. Finally got it all cleaned and back up and working. Needed a new main board ($170 on eBay) and replaced the camera lens sensor. But I have the purple flickering. Even on the SD card. I ordered new transmission cable and the other cables to the forward sensors. Should know in a few days if this fixes the problem. Any other advice would be appreciated.

Is it this board that you replaced:
✔Genuine DJI Mavic Pro - NEW Main Core Board A & Downward Vision Sensors | eBay
If so, I was thinking this was problem with mine. If this is board you replaced and you are still having problem with purple flickering, glad I didn't try replacing it.
Mine still takes pictures fine 80% of the time. Some have purple lines. If you ever figure it out I would love to know how to fix. Drone perfect except for purple line issue.
Still flies fine and takes great pictures. Still have the other 2 perfect Mavic pros bought from people who found them while hiking! Had minor crash problems.

ChipZ_601 · Nov 11, 2018

That’s not the one I bought. But I did find the post about the wire being pinched interesting. You definitely have a cable problem.

Dyno · Nov 11, 2018

ChipZ_601 said:
That’s not the one I bought. But I did find the post about the wire being pinched interesting. You definitely have a cable problem.

Definitely don't have cable problem. I tried one of my good complete camera assemblies. Only thing I have not tried is main core board. That is where video processing takes place.

FastHampster · Nov 17, 2018

how are you making out Chipz? I could replicate my issue by tapping on the front of the nose of the mavic. My phone would show a clean image and once i tapped the top of the front the purple lines would come and go out. If i tapped multiple times the lines would be intense and the camera would lose all single and the image on the controller / phone would be gray out. The purple lines also showed up on the SD Card as well. I started to make a video of the issue / repair and disassembly but when i saw the cable i just went to work and tested it without recording it. Only once has it showed it up since fixing it and it was really minor. Here is a 4k video of it. flying at the end of Oct

ChipZ_601 · Nov 24, 2018

Which cable? I did tap the front a bunch of times to see if it would go away or change and nothing made a difference.

FastHampster · Nov 26, 2018

Here is an image i got from the Internet. My video cable the small fine wires was pinched under the forward sensor. I did buy a video cable as you can replace it. I believed it was the cable as it would come and go and wasn't always consent. I would have to think if it was a chip the issue would always be persistent.

Kiwicbrthou · Nov 28, 2018

FastHampster said:
Here is an image i got from the Internet. My video cable the small fine wires was pinched under the forward sensor. I did buy a video cable as you can replace it. I believed it was the cable as it would come and go and wasn't always consent. I would have to think if it was a chip the issue would always be persistent.
View attachment 54395

They are a total pain in the *** and really easy to stuff up if you don’t connect them straight on.

ChipZ_601 · Nov 28, 2018

Yea, I replaced that one also after the issue. Still there. I'm not all that worried about it now, but if it's the coreboard I bought on eBay I don't have much more time to send it back for another one. So that's why I'm trying to figure out if the board could be causing the problem.

Dyno · Apr 26, 2019

HI, I'm back, got another Mavic Pro. I have every part there is, multiples of some, still have purple lines like in picture I posted. This interference, whatever it is, is there all the time. Fire up controller, start Mavic, just sitting there, not flying, no props turning, interference in video is there. I have changed COMPLETE camera assy. no help, have changed main core board, no help, have changed wifi module, no help, have changed GPS module, no help, have tried different ribbon cables, no help. Last possible thing to try is flight control ESC board, but that is sooo much work. Have had this Mavic apart so many times, could do it in my sleep. I have 2 other complete Mavic pro's that work fine, plus a lot of parts. Just ca't fix this one. What can it be??