PX4 main power supply option does no work anymore

The main power supply (the 6 pins plug connected directly to the 90A power supply card) do not work anymore. No light, no beep nothing. I try changing wires and controlling my power card, checking the plug, measuring voltage, everything is ok, I even had the opportunity to connect another PX4 to my config, the other PX4 was alive with 6 pins power wire.

Powering with the power rail (servo) is ok, and from USB it’s also good. What is strange, I still can get the I and U values and can read it with QGC, when I power it from the servo rail or from USB.

So my questions

  1. Is there something I can do physically in the board (trying to check one fault component and replace it)?

  2. Is it dangerous to fly with only the servo rail powered in 5V (BEC or diode saftety installed)?

Thanks for help. Chris

Hi Chris,

this is mainly a Software Discussion Board. If you are having HW Issues you have to contact the corresponding Company (as there are several and you did not state where your Board originates from, I can only guess that this is an original 3DR Pixhawk).

Measuring the Power from your PDB has nothing to do with the Supply Rail in the Pixhawk except for sharing the same physical plug. There are also several possible Problems which can cause this.

I doubt you should try and solder on the Board. Check the OpenHardware Shematics available here:
https://github.com/PX4/Hardware/blob/master/FMUv2/PX4FMUv2.4.5.pdf Page 12 covers the Power Input Rail.

Hi Andreas, Hope you will understand my message… (And I do not care if you want to banish me from the site).
To be clear, each time I try to get an answer from the community, I have this kind of answer: Where did you buy your hardware? As an Google user, when I try to buy something, I do a research, and what do you find? Bangood, Aliexpress, etc. Why do you think people doesn’t buy from 3DR store? Because I was on day on the 3DR site for buying a Pixracer. It was written Out of Stock. I asked on the contact form when will this item be available? No answer. So now, I buy from where I can buy, and I’m not sure I’m the only one. Now I had a look at the 3DR site, trying to buy a Pixhawk PX4, this item does not more exist, there is an unknow 3DR Pixhawk Mini I assume this is the New Pixracer… Great. If you are not happy with the definition of Open Source Hardware, this is really not my problem. If Chinese people doesn’t play the game and pay licenses, Stop Open Source Hardware, that’s it. What about financing the Software side? I just know that your team is a value team, and as I Swiss Citizen, I pay around XX’000CHF of Federal Tax each Year to pay a percentage of such Schools like ETHZ, that are doing a good job, I guess, and I’m proud of having such Schools in my Country, but Please, do not each time ask Where did you buy your material… And telling me This is Mainly a Sofware Discussion Board doesn’t help a lot, please consider ALL the Different available Forums directly linked to your related business (CGS, Mission Planner, Google groups and so on, etc. I’ve never seen a Simple Web Page to guide the New users enthusiasts. Try to think that other peoples than Engineers are enjoying flying with Drones and sometimes you really DO NOT HELP.

Got to go to real world job now, to pay taxes…

Hi Chris,

I’m really not part of the PX4 development Team. Nor do I work for or at the ETHZ. I actually do have a real world job - and thus paying CH Taxes as well. Helping giving advice to other users here is voluntary - don’t worry you will not pay my life.

Oh, and by the way I do actually love Open Hardware and it is really not the PX4 Communitys fault when you buy Hardware from doubtfull sources or of minor quality. There are also reliable sources for HW like: Drotek, Auav.co, etc. I could even find a Swiss Store that shows availability for the 3DR Pixhawk: https://www.eflight.ch/pi/3DR-Pixhawk.html
No need to blame the inventors and Software supporters for your choice of the seller.

That being said, lets have a look at your problem.

As for giving advice in such a thing there are probably a few legal implications. So I can tell you what I would do - which is no advice in what you should do.

If I were skilled with a soldering Iron with SMD I would have a look at the Power Plug first, and check that the Contacts are properly bonded. Further down (following the Shematic) there are 2 Transistors as well as a few resistors and the Power Controller. As this Controller also checks for USB and Servo Rail it will probably work but may fail on the Channel for the external Power. As the rest of the Pixhawk seems to work the problem should be located within these few parts.

Otherwise I would recommend to get a new Pixhawk from a reliable source.

Some Documentation can be found here: http://px4.io/user-guide/ or you may ask this friendly discussion board.

@chris66 We generally love to support users. There is just very little we can do about broken hardware. And the same way as a Linux user with a broken mainboard really should go to the vendor of his computer for support anyone using Pixhawk should get support and warranty from the vendor (independent what kind of vendor it is or where the vendor is located).

Wether or not the hardware design was open source really doesn’t matter at that point.

And its hard to support users in using semi-broken hardware - if we had felt that a power module is not necessary we would not have made it a default feature. So generally, as these things fly in Switzerland near houses in general: I do advise against flying broken hardware and there is a reason we made it kind of hard (putting software checks in place) flying without a power module.

Hi, once again, I’m really sorry if I’ve hurt someone, but the second point of my question was for me not related to hardware or software it was logical or safety point:

So I understand that a part of my hardware is broken or something, but the main point was this one:

Is it dangerous to fly with only the servo rail powered in 5V