A few days ago, I had a perfectly functioning heavy-lift Hexa drone from 3DR.  Now I have an awkward paperweight. This is VERY frustrating and I'm beginning to wonder if the APM 2.5 board is really the best choice for flight control. 

It all started to go south when I was attempting to access an extra servo via a spare channel.  As a relative newbie, the instructions were a little confusing.  Consequently, it was not successful, and while plugging the servo in, the MP software crashed.  During this process I may have also messed up some settings on the Spektrum DX7s radio.  I honestly lost track of every step as I seemed to dig myself deeper into trouble.

I have been tracing this issue for days now.  In the process I have essentially rebuilt the Hexa step-by-step.  I have calibrated the ESC's automatically, manually and automatically again.  I updated and reinstalled the MP software and driver on the PC - although the APM 2.5 firmware update keeps failing.  

Most functions seems to be working and connected.  I can see the radio working in the MP software.  I can make changes and calibrations thru the MP software.  I can see the APM 2.5 lights arming and disarming  (although somewhere along the way, the 2 positions seem to be reversed).   Yet the motors refuse to spin.

Am I missing something obvious?  I can't really find any other options to locate the source of the trouble.  Thx.

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  • Can you try a reset to factory defaults?
    Perhaps the program is corrupted.

  • I had nothing but problems with my APM 2.0 due to the GPS noise. Their solution was APM 2.5, and, BTW, I was told I could not exchange my APM 2.0 for APM 2.5.

    I solved the problem by purchasing a Wookong M. DJI did have a problem with defective firmware on the GPS, but they quickly replaced the defective part. My aircraft flies like a dream now and the GPS hold is incredible. Yes, WKM costs a lot more than APM 2.5, but it just works.

    I would not consider putting any expensive cameras on an APM 2.x

  • Do the motors spin if you do the motor test in CLI?



  • Developer

    You plugged the servo in with the power on? That's NEVER, EVER a good idea on ANY piece of electronics.

    So you said the motors spin when connected manually to the radio receiver? I'd start there. 

    If you can see the arming and disarming of the copter, you are in good shape. That means the radio is being read correctly and your radio calibration is OK.

    Open the CLI and run the radio test. Make sure the channels are all being read correctly. you should see CH1, 2, 4 are +- 4500, and CH3, CH 5 is 0-1000

    Anything else is probably a wiring problem. Triple check the wiring is all good. 

    If you do the ESC calibration by giving the APM full throttle, you will get a passthrough to all ESCs when you cycle the power the first time. You should be able to make the motors spin. 

    IF you do these things and the motors only spin when hooked up directly to the radio, you have fried the output pins on the APM by plugging in a servo incorrectly. Being one pin off when plugging in with power will kill any controller board.


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