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help after crash

Discussion in 'General Discussion' started by mintakax, Dec 21, 2013.

  1. mintakax

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    In my stupidity I let a friend fly my phantom1 in attitude mode and he hung it 40 ft high in a tree. I was able to toss some twine around the branch and shake until it fell, but it had a hard fall. All looked OK,, but it is now badly unstable in GPS mode. I am able to fly it in ATTI mode, but as soon as I switch to GPS it flies away until I switch back to ATTI.
    It initializes normally as far as LED sequence. After sat acquisition I get all green blinks and then home lock sequence.
    This is what I have done so far to try and fix it:

    compass cal
    Tx control cal in assistant
    Advanced IMU cal in assistant
    Pulled off shell cover and inspected all connections including GPS board (all appears fine)
    replaced all props with new ones

    I'm not sure what to do next. Any ideas ?

    Thanks
     
  2. runnerman

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    You might want to try taking the IMU out and hitting it on the opposite side you crashed on. Only hit it once. It sounds stupid I know but it usually works.


    Sent from my iPhone using Tapatalk
     
  3. runnerman

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    You might want to try taking the IMU out and hitting it on the opposite side you crashed on. Only hit it once. It sounds stupid I know but it usually works.

    Hope this helps!


    Sent from my iPhone using Tapatalk
     
  4. mintakax

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    Thanks ! I'll probably do that, but since it tumbled out of a tree and crashed when it hit the ground, I don't really know which side it crashed on. Also, I was wondering if the fact that it flies fine in ATTI indicates that the accelerometers are not stuck ?
     
  5. Driffill

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    Pop the hood and under the top cover is the GPS puck, peel offf the foam and undo the four tiny screws holding it to the shell and take it out, you will probably find the the ceramic antenna of the GPS is broken :( it's on the top side of the PCB board.

    That would explain the lack of GPS lock.
     
  6. mintakax

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    Thanks
    If that was the case, would it still be able to acquire > 6 satellites ? It is doing that.
     
  7. Driffill

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    In all honesty, I don't know?

    I've heard of people finding a cracked GPS antenna after a crash etc, but I can't remember if they had communication with the satellites etc or not. I'll be interested to hear how you GPS puck is . . .

    If its cracked but still connecting, I might need to inspect my puck more often than I currently do to be sure there is no damage.
     
  8. mintakax

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    Thanks Driffill
    I checked it yesterday, but didn't pull it off, so thats what Im going to do next. At any rate, my problem has to be GPS related, so the puck is the first thing to check/replace.
     
  9. Cosmos Kid

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    I have been experiencing the same problem with my Phantom. Crashed the last 3 extremely short flights due to drift and being uncontrollable. I finally stumbled upon this thread and this could be the answer. I had a bad crash a while back, but didn't have any drift or runaway problems until recently. Stupid me never thought to try and fly in atti mode. I will give it a go as a test.

    I did notice upon inspection after the last crash (I experienced a runaway and ditched the thing before it got too far away) I noticed one of the arms on the lower body assembly had cracked. Would that be a factor to weird flying at all? Can a guy just make simple repairs?
     
  10. mintakax

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    I finally got around to installing a new GPS unit on the crashed phantom, but unfortunately it did not fix the problem. It's weird because it flies perfectly fine in ATTI mode. Once I switch to GPS, it behaves as though there are elevator and aileron inputs, I can sort of control it with compensating stick inputs. I can send back the puck ($150) and I suppose the next thing to try is a new FC, but that is almost 1/2 the cost of a new phantom. Advanced IMU and compass all calibrate ok.
    Any ideas?