My Gimble needs help

[ruggb]

I have a crashed MP. It did not socially distance from a tree and appears to have hung around the branches for 20 minutes videoing its landing spot b4 shutting down.
Eventually, it blew down, ripping the camera/gimble off the mounting plate in the process. Damage was 1 arm mounting piece, 1 servo cable, 1 video cable, 1 gimble mounting plate, 1 plastic wire cover, and slight damage to the props (you have to look for it). The cables were ripped apart as opposed to unplugged.

I have replaced all the parts and fired it up. I am testing this via WiFi as this unit was given to me as is without a controller. The owner bought another AC. The Gimble goes thru a power up sequence but does not end up in its normal position. There is no video. I cannot run the gimble calibration as it locks up the app with the TIP, "Gimble calibration complete. Do not turn off the aircraft." I cannot move the gimble using the app.

IMU and Compass calibration was done.
What is the next obvious problem.
If not obvious, then how should I proceed to check it out.

 

[JohnnyD913]

Replace both camera video cable and gimbal ribbon cables

 

[ruggb]

Per my post, everything except the camera was replaced.
So how will the camera make the gimble work?
And why does the gimble appear to do a startup calibration then not function at all from the app?

 

[MAvic_South_Oz]

Johnny recommended you replace the "camera video cable", you posted that was damaged.

 

[JohnnyD913]

Do you have video?

 

[MAvic_South_Oz]

OP said . . .

Damage was 1 arm mounting piece, 1 servo cable, 1 video cable, 1 gimble mounting plate, 1 plastic wire cover, and slight damage to the props (you have to look for it). The cables were ripped apart as opposed to unplugged.

I have replaced all the parts and fired it up. I am testing this via WiFi as this unit was given to me as is without a controller. The owner bought another AC. The Gimble goes thru a power up sequence but does not end up in its normal position. There is no video.

Not sure if there WAS video before the repair ?
Probably not.

So much to assume here, like is the Control Mode switch to WiFi before starting the drone up ?

 

[JohnnyD913]

OP said . . .



Not sure if there WAS video before the repair ?
Probably not.

So much to assume here, like is the Control Mode switch to WiFi before starting the drone up ?

No I never use the WiFi switch.
Try switching it off that

 

[MAvic_South_Oz]

If flying or powered up with the phone by wifi (no controller), the wifi switch is moved to that position (in the USB port on the drone).

 

[ruggb]

I seem to have a problem communicating, but I don't understand what is not clear about this:
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Damage was 1 arm mounting piece, 1 servo cable, 1 video cable, 1 gimble mounting plate, 1 plastic wire cover, and slight damage to the props (you have to look for it). The cables were ripped apart as opposed to unplugged.

I have replaced all the parts and fired it up. I am testing this via WiFi as this unit was given to me as is without a controller.
==========

Since I stated that I am testing it via WiFi and seeing the app and not seeing video, and not able to control the gimble, might it be a good bet that the unit is running in the WiFi mode as opposed to the need to ASSUME that it is? Maybe not! But I don't believe the app will run if it is not connected to a controller or AC.

I read something I find is very true. "Most people listen to answer not to understand."
Please tell me how I can be more clear.

The crash involved a tree.

=========
and appears to have hung around the branches for 20 minutes videoing its landing spot b4 shutting down.
=========

as seen on three files from the SD card. So it was functioning prior to the fall. Branches stuck in the gimble assy are the likely cause of ripping the wires out when it fell.

======
The cables were ripped apart as opposed to unplugged.
======

That might suggest that it would have been impossible to have video before the repair. But I admit that because the cables were totally separated from side to side, I did not try to test it b4 the repair. The only thing holding the camera to the AC was 2 rubber shock absorbers.

I can provide pre fall video or video of the power on movement of the gimble if that will help. But after that, the camera is not facing forward and the gimble is unresponsive. Does that indicate the servo operation during powerup is causing the system to shut them down. That would be the best senerio I can come up with. But how to verify it b4 replacing the whole gimble assy? And what about the video?

Thanks for understanding.

 

[MAvic_South_Oz]

I seem to have a problem communicating, but I don't understand what is not clear about this:

You have no controller.
You are testing by wifi mode using a phone / ipad etc.

Correct ?

Are you doing the wifi mode connection following the manual instructions ?

https://dl.djicdn.com/downloads/mavic/20171219/Mavic%20Pro%20User%20Manual%20V2.0.pdf

Page 48 - Using Mobile Device to Control Aircraft

If you still have no video, there are probably numerous things that might affect this.
Not something easy to diagnose, most repairers will just try replacing various parts until the error is fixed.

 

[ruggb]

Thanks for the link to a manual.
Yes, I have experience MAY people who think they are repair people who are merely parts jockeys. I what to have a good idea of what the problem is b4 I start throwing money at it. That is just the way an engineer works. Been one of those for 55 years.

For those who are not aware, if you start the AC THEN switch to wifi, the wifi will not start, meaning there is no signal. Without a signal my phone will not connect to the AC, without a connection to the AC the app will not start.
So if my app has started and I am not seeing video or cannot control the gimble, then I am connected to the AC and therefore the WiFi is running and therefore I must have done that all correctly.

I guess the first thing to do is to disassemble and verify that I have seated all the connectors properly. Since there is only 2 on the video cable, that could be an issue. Since the gimble does try to do a power up calibration, I suspect the cable is connected OK, I just have to more closely observe what it does as one of the servos might not be servoing. That may be a good reason to upload a video of that. Someone might see/not see something I don't see or realize is missing. But, I would think if there was an issue with the POR it would give me an error. None seen.

 

[JohnnyD913]

Gimbal control board
Sounds like to me

 

[ruggb]

That is the one everything plugs into on the AC, right?
I would suspect that if the cable break caused it damage it would be on the drive circuit and it would not move the gimble at all. HOWEVER, after more careful observation I see that the middle servo is not doing anything during the POT. I will recheck that connector. Otherwise, you are probably correct. Since the video also plugs into that board it is possible both failures are either cable connection or the board.

 

[JohnnyD913]

That is the one everything plugs into on the AC, right?
I would suspect that if the cable break caused it damage it would be on the drive circuit and it would not move the gimble at all. HOWEVER, after more careful observation I see that the middle servo is not doing anything during the POT. I will recheck that connector. Otherwise, you are probably correct. Since the video also plugs into that board it is possible both failures are either cable connection or the board.

Let us know

 

[ruggb]

Let us know

There is some success here. I have the gimble working but still no video.
I checked and reseated the center servo connector and camera video cable connectors. I couldn't tell if that was the problem, so I inspected the connectors on the board very carefully and there appeared to be a film like wiped sealant over a few pins. I pulled that off, finished the job and the gimble is functioning.
Now video. Any suggestions on testing?

 

[JohnnyD913]

There is some success here. I have the gimble working but still no video.
I checked and reseated the center servo connector and camera video cable connectors. I couldn't tell if that was the problem, so I inspected the connectors on the board very carefully and there appeared to be a film like wiped sealant over a few pins. I pulled that off, finished the job and the gimble is functioning.
Now video. Any suggestions on testing?

Glad to here u have video and gimbal works.
I have never been in WiFi mode so I’m afraid
I’m of no help there.

 

[ruggb]

Maybe I spoke to soon. When calibrating a gimble:
1, how long does it take?
2. does it require video?
I still don't have video and the app won't even switch to video but it makes believe it is taking pictures when I touch the button.
When I try to calibrate is seems to stay at 5% and the gimble moves very slightly. When I hold the AC and move it, the gimble appears to be holding the camera position - not sure how well since I don't have video. and I can move the gimble up/down from the app.
Sorry, that should have been NO VIDEO in the last post.

 

[MAvic_South_Oz]

but it makes believe it is taking pictures when I touch the button.

Do you have a micro SD card in, and does it actually take a photo (or video if in that mode) ?

 

[JohnnyD913]

Idk bud. I think it’s either the gimbal itself,
Which means motors.
I bought the gimbal assembly with ribbon cable off eBay recently for $35 US dollars.
The gimbal control board if bad would prevent video/ pics as well

 

[MAvic_South_Oz]

Just wondering if it actually did record a photo, when it makes the camera photo sound.