Only one motor spins up

I am the coach for Louisiana region 5 stem center and we are experiencing an issue where we only have 1 or two motors at most spinning up. After 4 days of back and forth through the guides for our team, I walked them through pulling everything apart, we then took the m1,m2,m3, and m4 wires and applied them to the break-out board port 1 that always spins. we confirmed that every motor spins and they are in the correct orientation. They have tried using windows and linux to flash the firmware and no change. What are we to do? We will be back at it at 6 pm trying to get it working and can use any advice.

Can you clarify what you mean by “breakout board”? Are you talking about the PWM module that plugs into the FC? If so, perhaps you can take a video of what happens when all motors are plugged in and you try to arm the drone and give throttle. Also, have you done an ESC calibration?

Yes the PWM module. i will take video of it and drop a link. we have done the ESC calibration several times now.

here is the link to the video.

In the video am I hearing that not all motors are doing the 5 tones? Can you go to the summary screen in QGC and tell us what firmware version and what airframe you have selected? If you have confirmed previously that all motors spin when plugged into port 1 of the PWM module I’m led to believe you ESC is okay but either we’re dealing with a FC software/config or hardware (hopefully not) issue.

here you go. we appreciate your assistance.

A couple more things that come to mind (I’m running out of ideas!):

  • When you run the motor test in QGC do you see the same behavior as when you arm? Only motor 1 spins and the rest do not?
  • Your Pixhawk shipped with two PWM breakouts. Can you try the other one?
  • Inspect the cable that goes between your Pixhawk and PWM module just to make sure no pins haver come loose

After that I think I’m out of ideas and let’s get a new one shipped to you. Please let us know your test results. Also, when is your team competing?

motor test: only motor 1 spins up.
breakouts: we tried both of them and have the same thing.
Cable: we can not find any loose cables.

I am worried it is an issue with the pixhawk as seems to be a software issue.

One more thing (I promise not to say this too many times)… let’s do a firmware update to PX4 v1.13.1 and see if that does anything for your motors. Update to the version shown in my screenshot and then run a motor test.

where do we get that version from?

Just open up QGC. Select the firmware tab. Then connect your drone via USB. You’ll get the popup from my screenshot. It’s the current stable release of PX4 and is downloaded from a remote server when you click Ok.

okay we will go try that, and i will post results.

we have the correct firmware, we did try a firmware update, but nothing came of it, only motors 1 and 3 spun up with the motor test.

Very strange that you get 2 motors spinning up when originally you had 1. I’m going to recommend that you request a new FC by sending an email to Also, if we could coordinate shipping your old FC directly to me it would be much appreciated. I’d really like to diagnose this issue and understand what’s going on. When you get the new FC you will need to go through the firmware/calibration process again. A good FC makes this process much more enjoyable. Sorry for all the trouble.

email sent, i do not know the logistics of getting one in time, if nothing else could someone meet us at the event saturday am with it?

Absolutely. We did this for a few teams this past weekend in Arlington. Will you be at Arlington this weekend? I will coordinate having someone to assist. BTW we will have a tech support table in the pit area that can assist with any and all technical issues related to AVR.

Yes we will be there. driving up friday night and will be there at 8 am saturday. We appreciate it once again.

I will not be at the competition this weekend but @nbrownback-bell (Noel from Bell) will be there. Please ask for him and he’s aware of the issue. I told him to give me a call if he needs any technical details. Thanks for your patience and good luck this weekend!