I hope this helps as I hate wasting anyone's time. I am speaking in lay terms and may use incorrect "technical" terms, so I hope you understand what I am describing. Last year I had a similar problem with my P4. I never crashed or landed hard. I bought it used and it only had about 50 flights on it and was owned bythe original owner for about 6 months. I first noticed a pinkish tint when recording video and only on playback. The FPV on my iPad mini 3 was fine while flying but the pink interference was on playback first when playing back after landing and then it creeped into the SD recording. It then started showing on still pictures, but that was a test because I rarely shoot still pictures. At all times FPV during flight was clear on my display was clear. I received no helpful info when I called DJI and here in Honolulu, Oahu, Hawaii we have one drone dealer/repair shop, Drone Services Hawaii.
The repair tech gave me the following info and again this was a P4. 8 screws hold the gimbal and camera to the drone. If you remove the screws and detach gimbal camera there is a circuit board that includes the port for plugging in a micro usb male connector and a port for the SD card. The data goes from camera to that circuit board (see attached picture. The circuit board I am describing is just above the guy's thumb). The tech told me that all the data is processed on that little board and on that board is a sensor that the info passes thru and when it malfunctions it can start by producing a form of interference, in my case the pinkish tint that resembled the "snow" I used to see on empty UHF channels. If you weren't around before cable you may have not seen it before but I can best describe it as a "finer" snow then what you would see if saw "snow" interference on a regular empty cable channed (if it didn't just go to black screen) and in my case it was a pinkish tint.
Unfortunately that little board is not replaceable by itself. I wound up purchasing a new "gimbal/camera" on Amazon for $399 and right now, a year later, that is costing $499.00. I just swapped it out and in the time it took to connect the two flex cable connectors to the drone body and replace the 8 screws I was good to go. If you could find a similar crashed drone and buy it for parts you could possibly swap that board out if you have the time, skill, tools and patience to do the job as well as the tolerance of the video presentations of people who post on You Tube who I find to be difficult to watch for a variety of reasons and DJI does have some tutorial videos on their site, is they haven't taken them down. I am having that problem now because the best DJI P4 disassembly video tutorial that I came to rely on apparently has been taken down by DJI unless someone knows where it is now located.
Also, I have come to amass alot of spare parts and after a while you may have an inventory of spare parts that you can use to make future repairs like I do. Since buying my drone, I have purchased 2 additional P4 drones that came with no gimbal or camera which cost $299 each and I bought another camera as well. After that first replacement over the following year I hit a cliffside by the ocean and the other time my drone was just sitting on the beach and got hit by an unexpected large rogue swell that came up 75 yards further up the beach that normal, like a mini tsunami wave and submerged the drone. Bottom line is if you don't quit after disaster strikes and you do your own repairs, it seems that in the end you will ultimate make use of everything when scavenging to get back up in the air.
Good luck. A hui hou!
Aloha,
Mark Povraznik
DronePovraznik
