Pixhawk 4 Hardware faulty?

I’v received my Pixhawk 4 today.
I’ll go step by step what I have found happening:

First I plugged in the Pixhawk 4 to my usb port, just to do a quick check, etc. It booted up fine. But I’ve noticed that it intermittently starting to reset after a few seconds.

I plugged in the GPS module so that I can hear the buzzer and see status LED. Boot up fine and the power up tune played. Status LED went soft pulsing blue. Again I noticed the PixHawk reset intermittendly (At this stage I was thinking faulty USB cable).

Then I tried to connect to QGC and had no joy. Tried Mission control and also no joy.

While I’m still checking my port settings, I noticed something else, When it reset itself like that, the main indicator LED on the GPS goes off, the ACT, B/E and PWR led lid constantly on the FMU (actually with a slight flicker). the PWR, B/E lid constantly and the ACT led flicker (like normal) on I/O. Resetting the I/O works but not the FMU.

Then, the above state of LEDs started to stay like that permanently.

Obviously, I tried doing a firmware upgrade, but that does not work because of the no connect.

I tested a Pixhawk 2.4.8 with the same cable and settings, QGC and Mission control and it works perfectly.

Is there a hard reboot method I can do to clear the Flash and bootloader and try over?

Or is it just hardware?

Sorry for the long post. Have to make sure I covered everything before ordering a replacement.

1 Like

Hello! Could be a USB connection issue, without the physical hardware, it’s hard to diagnose at this point. You can contact Holybro’s product service team at productservice@holybro.com to ask for a RMA.

I would suspect that it almost seem like your USB doesn’t have enough voltage/amperage to maintain and sustain the needed power level. Have you tried powering it first via the PCB then connecting via USB?

Good luck.

Thanks for your replies.
It is not an USB power problem.
I have tested an older Pixhawk 2.4.8 with the same USB cable that came with the Pixhawk 4, all good.
I have also tested with an original Raspberry power supply capable of delivering 2.0Amps, which is more than enough.
Next step would be to use the Power PCB with a LiPo, but I know at this stage it would make no difference.

The Pixhawk 4 is not going through its boot up sequence. I think a FMU part failed.

@JingerZ, thanks for the link to contacting Holybro, but I did not buy it from them direct (Banggood, which is an original Holybro supplier). First I want to sort it out with them to get a replacement. If not then I’ll contact Holybro.

I made a video

Manufacturer confirmed it is a FC problem. Sending me a replacement. Was not a hassle to get sorted via Banggood, just a delay due to the Chinese October holidays. Closing subject.

1 Like