I'm on my second P4 Pro this month.  The first one had a terrible yaw drift on the gimbal, and I couldn't get it sorted.  Second unit arrived today and after a half hour on, I'm getting a "compass 1 disconnected" error intermitantly.  Shaking or tapping the phantom can get it to come back to life, and then it disconnects again.  Before I go out and buy a third unit tomorrow morning for my shoot in the afternoon, I'm thinking about checking to see if the compass cable is not seated completely.  Or is the compass built on the flight controller.  Any help on where to look for an unseated cable would be great.

Aloha fans577,

     This sounds like a real pain.  On the up side you have two compasses.  Have you gone into the DJI GO 4 app and looked at your compass read-outs?  Unfortunately, any attempt you may make to re-seat the cable will void your warranty.  The connection is inside.

     In the General Settings (Icon in upper right corner) tap on the Aircraft settings icon (top left).  In there look for Sensors and tap on it.  Then tap on the compass option and check the two compasses for their performance information.  If the compass 2 shows good performance and you have already calibrated it, give your bird a test flight.  Let us know how it goes.

     If the stars are aligned right for you, this might buy you enough time to do your shoot and then get the Aircraft fixed.  On the other hand, what you are experiencing is the reasoning behind having a back-up.  

     Hope this helps!

Aloha and Drone On!

Thanks for your reply.  Yes, I've been to the compass readouts and can see exactly when it's disconnecting, and then reconnecting.  It seems like I just have another bad unit.  I have plenty of backup, 2 mavic systems and a few solo/gopro rigs, but was really looking forward to using the upgraded camera on the p4 pro today.  I'm waiting for bestbuy to open so I can hurry quick to get another system.  The current was my second from Amazon this month, they take DOA returns with no hassle.

Phantom 4 Pro's compasses are mounted inside the landing gears. I am sorry for the difficulties you are experiencing. Please check if you can upgrade the firmware first. If the drone owns the latest firmware and the compass still remains disconnected, I would recommend sending the drone back for repair instead of repairing it by yourself since the damage caused by unauthorized modification, disassembly, or shell opening not in accordance with official instructions or manuals will not be covered by warranty according to DJI After-Sales policy. Thanks for your understanding.

If not a former firmware is known to give a "Compass 1 Disconnect" how should a firmware upgrade help solving this issue?

With all chances that everything else go nuts after upgrade to latest firmware i really wonder how DJI support can give this advise to a customer in need of a working equipment!

Best luck getting your work done one way or the other.