Phantom 4 Pro. IMU Error. Accelerometer/Gyro disconnected.

[natetheok]

Phantom 4 Pro.
Unable to Calibrate IMU. (Error Status)
Willing to try anything suggested.
I've already tried numerous things like restoring to factory defaults and re-installing the firmware.
Attaching 2 screenshots.
Errors occurred after small crash inside. (Lesson learned)
Any advice would be greatly appreciated.

 

[Goof]

It looks like your FC board has either disconnected or broken the ribbon cable between the FC and the 3-in-1 board. You can try everything ranging from compass calibrations, factory resets, turning it on and off again and firmware refreshes, but I suspect none of that will help you.

If it's in warranty, or DJI Care, I'd look into sending it back for repair or replacement. If it's not, and you're feeling adventurous, you can maybe take the camera module off and inspect the cable linking the little rubber mounted board with the big board with the heatsink. It may be loose, broken or corroded.

 

[natetheok]

Hi Goof,
Thanks for the reply.
I just purchased this drone from Best Buy less than 2 weeks ago.
So with respect to sending it back to DJI for replacement/repair would this be considered still under warranty ? I'm new to all this drone stuff.
I do feel comfortable with atleast taking off the camera module as you've suggested and atleast taking a look for any loose connections. Unfortunately, I'm at work, so I will have to try this later this evening.
I agree with you though, I believe it is just something that has become physically disconnected.
I didn't specifically mention it in my original post, but on the IMU calibration page... when I click on the Compass tab. I do atleast see readings there... ie, the compassses do not show as being disconnected.
Another thing I tested also, when I connect the drone directly to the PC and run the Simulator in the DJI Assistant application... i can see parameter values changing when I manually lift the drone and move it around, but the Accelerometer and Gyroscope values stay at 0. I'm assuming this isn't normal, but I never did this when the drone was functioning correctly.

 

[Goof]

Hmm.... Compasses are in the legs, and they're connected to the power board at the front of the drone. The power board is then connected to the right ESC and the FLT_CTL board, where the IMU is. If the FTL_CTL board was completely disconnected from the 3-in-1 then you'd lose communication to the power board and the compasses, so we're left with these posibilities:

- FLT_CTL / 3-in-1 ribbon cable only partially broken or only just maintaining connection (most likely)
- Impact damage to the FLT_CTL board, unlikely IMO but not impossible
- Some other weird issue with the 3-in-1 board (unlikely IMO)

I'd have a chat with the guys at Best Buy, see what their own warranty policy is and whether you can get an exchange unit due to the 'mysterious' IMU issue. They might tell you to talk to DJI, at which point you'll need to ask them the same question "Can I get a replacement or repair for this IMU failure".

Depending on where your moral compass swings, and also depending on any obvious physical signs of crash damage, you can omit the fact it's been crashed. Crash damage is NOT covered in the warranty, so you'd likely have to front the repair cost if you send it to DJI for repair. ($100-$200+? only guessing, haven't personally had to send anything in)

If you want to go the "warranty be damned, I'll fix it route", I think the FLT_CTL boards can be bought off places like EBAY, or other RC parts stores, at least they can for the P4. You can also get cable kits for the P4, not sure if they work or not for the P4Pro though...

EDIT: If this is the P4Pro board, it looks a lot different to the P4:DJI Phantom 4 Professional Pro + Main Control Unit Anti-Vibration Brackets Drone

Looks as though that board has the crappy press fit connectors instead of the tab style ones on the P4..... Either way, until you decide if you want to try for warranty or void possible warranty and open it up, we won't know...

 

[natetheok]

ok, I'm planning to go for the 'No Guts, No Glory' approach of trying to fix this myself. I plan to video the process so if all goes well I will post it in hopes that it will help someone else. Before I begin this adventure I do have 1 quick question if someone could help answer I would appreciate.

2). When my drone is connected to a PC (via USB) and DJI Assistant 2 App is running (in Simulator mode).
If I manually lift the drone and move it around... only the gimbal values change. The Accelerometer or Gyro values never move from zero. My assumption is that this definitely shows that these are in fact disconnected or not operational, but I don't know for sure if these values change when a drone is working properly.
Can someone confirm that when the drone is operating normally that these values should change?

 

[Goof]

On a P4 they definitely change as you move the bird.

I've been looking at the internals via videos and it turns out the cables are set up differently on the P4Pro. The IMU board has two cables that link it to the 3-in-1, one on each side. You'll have to inspect both of them. and make sure they're firmly attached and not broken

These guys Phantom 4 Pro Parts and Service are selling parts for the P4P, so if you can't find any issues with the cables, or do find a break it's good to know you can get hold of new cables or a new flight controller...

 

[Justinrobling]

Same issue here...only one of mine are disconnected. The drone recently took a smaller crash not this error pops up. I have the drone all disassembled an all the cables are connected. This is phantom 4 regular. If you have an advice I’d really appreciate it.