Hello.

I'm quite experienced electronics and drone technician, however I have encountered problem  that I cant get my head around. I repaired my friends phantom 3 pro after crash. The gimbal  yaw arm, and cable has been replaced. Everything was fine it was rock solid image transmission, but upon testing, my "friend" started to blame me for not fixing the noisy roll motor. it was making grinding noise when forced with finger or when drone rolls heavily. I have replaced roll motor. Noise stopped. But now drone keeps showing weak signal error. sometimes it catches the video signal and loses it again. Screen stays black, or top part of a screen gets the image, but rest of the screen turns green. Took few pictures and video. Image files have been saved on memory card with no visible problems, so this is related to image transmission between drone and remote/app. cable is not damaged, I used genuine parts. Could it be bugs in firmware or something related to replaced motor? I have repaired around 20 phantom 3's, and over 50 phantom 4's, mavic's and inspire's - never had issue like this. Any ideas? Could downgrade of drone firmware help?

Any help appreciated.

Thanks!

Hello, Well it would seem that the firmware is not liking the replacement parts. as this issue is strange i have come across it as well, are the replacement parts made within the same year as the drone?

and can i also ask for the system log file by connecting the drone directly to the computer so i can look into it further.

The micro usb port is under a flap under the phantom 3 badge, you may know this but just in case.

hope to help further.

Had this problem when I replaced the flex cable with a non-oem one. Looked identical, but didn't work. In this flex not only travel the motor power and commands, but also the video signal. After many strange problems replaced with an original and all was ok.

Hello people, thanks for replies.

I found the issue. So apparently my friend was upgrading remote to 1.9.3 and it was giving continuous red led blink and bleeping. He downgraded it to 1.6.0. And I read that 1.6.0 is not compatible with 1.11.20 of the aircraft. I tried upgrading to 1.8.0 but it fails download, and it fails update to 1.9.3 with beeping error again. I connected my own controller from my Inspire 1 running 1.9.3 and got solid image transmission. So problem was his remote all along so problem solved. He will get his remote replaced or reflashed. Thanks for everyones attention!

You are evidently very good at repairing drones.  Keep up the good work!

ALABAMA Posted at 2017-11-4 05:47
You are evidently very good at repairing drones.  Keep up the good work!

Thanks! Although, not sure if you're sarcastic or not.

I'm trying to get better and so far I'm good with mechanical repairs. Been repairing computers and phone for 15 years. Then building drones for me and friends. Then repairing them.  I'm not so good with firmware or similar issues, but confident about hardware.

So I hope you're not sarcastic and I will take the compliment and encouragement.

Thanks

By no means being sarcastic, lol.  Don't know why you would think that. I could tell by your post that you were very knowledgeable, and didn't mind asking for help when needed.  I like that, for what it's worth.

You can try to refresh the firmware, adjust the antennas. If it doesn't help, you can send the drone back. Here is the link for applying an online repair: https://repair.dji.com/en/SelfRepair/Area
We will do our best to help this out. Thank you.