Pixhawk 6C mini Holybro usb turned off by mistake HELP Needed ASAP!

Pixhawk
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Pixhawk 6C Mini Soft-Bricked (Serial Ports Disabled) - Need DFU/Hard Reset Method

Hardware:

  • FC: Holybro Pixhawk 6C Mini

  • Target Firmware: ArduSub (Stable)

  • OS: Windows 10/11

The Problem: I accidentally “soft-bricked” my Pixhawk 6C Mini by setting RC_PROTOCOLS = 4 and, critically, disabling the USB serial port parameters (SERIAL_PROTOCOL = 0 for all ports) to fix a PreArm error.

Now, the board refuses to connect to QGroundControl or Mission Planner. It powers up (LEDs on), but the GCS times out waiting for a heartbeat.

What I Have Tried:

  1. Firmware Swap: I flashed PX4 Pro, and the board does connect successfully. I can see parameters but nothing updates in the parameters.

  2. Re-flashing ArduSub: As soon as I flash back to ArduSub (even using “Full Chip Erase” in QGC), the board stops communicating again. It seems the bad parameters are persisting in the FRAM or bootloader sector that QGC is not fully wiping.

  3. SD Card: I have tried booting with and without the SD card.

  4. Driver Fix: I have uninstalled/reinstalled drivers and used a different USB cable.

The Main Obstacle: I need to perform a hardware-level Full Chip Erase using STM32CubeProgrammer to wipe the bad parameters permanently. However, the Pixhawk 6C Mini does not have a physical BOOT0 button, and I am struggling to enter DFU mode.

Questions:

  1. What are the exact pads/pins I need to short on the Pixhawk 6C Mini PCB to force DFU mode?
2

In mission planner, there is a button that says “force bootloader”, which resets the board into bootloader mode. Does this get you past the blocker?