Have i got 2 duff units? solid red on boot on one and no led at all on the other

beginner here so if anyone can help that would be apreciated.

ordered two units from bangood.

first unit does not show ANY LED light on boot but does make the usual noises but will not connect to mission planner.

unit 2 was working, but … this morning the telemetry module is locked into bootloader and the unit is showing a solid red LED and is completely unresponsive to any connection request.

both units are the 2.4.8

Those units are having problems for sure. I’d suggest re-flashing from bare metal using the STM bootloader and DFU-utils over USB. This means you will have to take them apart and track down the BOOT0 signal on the board, and short it to 3.3v while powering up the board. I’ve got a couple of the 2.4.8 boards, but I’ve never looked for the BOOT0 pad. It’s likely there are two pads next to each other that you can short with a screwdriver or something. I’ve got one at the office, and I can help you find it if you want.

I would be interested in that if you could see your way to looking for that boot 0

OK, I found the spot to activate the STM32 bootloader. I’ll post some pictures shortly and show you how it’s done. You should read up on the DFU-UTIL process in the meantime. Are you using Windows or Linux?

I made some instructions for putting the Pixhawk 2.4.8 into DFU flashing mode. See the picture here:

Once you do this, you will be able to load a binary image into the STM32 flash using a DFU-utility. The process is different depending on which OS you are using, Linux or Windows. Let me know and I’ll walk you through it.

I’m on Windows, those instructions would be very helpful to me. . . . Thank you.

OK, First you need to download the DFuse software from STMicro and install it:

Once that is installed, then you follow the instructions shown on the photo that I posted previously, to put the Pixhawk into DFU mode.

Now, you run the DFuse software, and you should see a screen that looks like this picture:

You should see something like “STM device in DFU mode” in the upper left box. If not, then go try again to put it into DFU mode.

Once your board is detected, you will use “Choose” under “upgrade or verify” to select a DFU file. I’ve already dumped my pixhawk 2.4.8, so grab this file and use it for this part.

Next, click the “updgrade” button, and your flash will get erased, and re-written.

Now you should be able to cycle the power, and your board should boot normally. If you have trouble, this video will help you with the process:

Good luck, and let me know how it goes.

@bigfinger I’m no expert but might I suggest to do the following first before tearing it apart.

  • Change and use a different USB cable.
  • Reformat the SD card using FAT32 or change it to at least a Class 4. Clas 10 is highly recommended.
  • Download and install QGroundControl
  • With the Pixhawk unplugged, open QGC and click on the Firmware tab.
  • Plug in the Pixhawk and see if it allows you to upload a firmware.
  • If it doesn’t then you know for sure you’ll need to do as @macphyter recommends.
  • If it does, choose the PX4 stable version. Make note whether the bootloader is V4 or V5. V4 is the 1MB limitation and you might want to update that to the V5 to take advantage of the 2MB capacity of the v2.4.8. You can follow the Bootloader Update procedure.

Good luck.


the dl comes in as dfuse demo? not sute why backtracked an that the only one availabe…

you my friend are defiantly on my Christmas list… all done and the red light has completely gone, normal service has been resumed.

thank you very much!

however… this is when it gets odd… works fine and dandy on usb. lovely, behaves as it should.

AS SOON as an external power source is applied … same issue of red light. video below shows the problem, with two different batts and bec’s … as i thought it might be a problem bec to begin with.

about to try a brand new pixhawk straight out of the bag… ill report back.

Edit: yeah seems like this is a board issue that does not seem to affect anything else. highly annoying though !