Pixhawk 6C: I/O B/E LED flashing red continuously, even after firmware reflash (PX4)

Pixhawk
1

Hello everyone,

I’m encountering an issue with my Pixhawk 6C (manufactured by Holybro) and would appreciate confirmation on the diagnosis:)

Hardware: Pixhawk 6C

Firmware: PX4 (I have tried both v1.14 Stable and the v1.15 Release)

**QGC Version:**v5.0.6 64bit

Core Symptom:

The B/E LED on the I/O processor side of the flight controller is flashing red continuously after boot-up. The FMU-side LEDs (PWR, ACT) appear normal.

Detailed Description:

  1. I am connecting the flight controller to QGC using only a USB cable. No peripherals (GPS, RC, motors, etc.) are connected.

  2. QGC successfully connects to the flight controller.

  3. I can navigate to the “Sensors” page, and the IMU (Gyro, Accel) calibration appears to work.

  4. However, the I/O B/E LED flashes red the entire time.

Troubleshooting Steps Taken (Which did not solve the issue)

  1. Reflash Firmware: I have used QGC to reflash the “PX4 Pro Stable Release (v1.16)” multiple times. The problem persists.

  2. Change Firmware Version: I flashed the “release/1.15” version. While this did cause QGC to show a “Missing Parameters: COM_DL_LOSS_T…” warning (which seems like a version mismatch), the critical problem—the I/O B/E red light—still persists.

  3. Confirm Location: I have confirmed it is the I/O side B/E light flashing, not the FMU side.

My Question

As I understand it, under PX4 firmware, a flashing red I/O B/E light indicates that the I/O processor failed to boot, or the FMU failed to load the firmware onto the I/O processor.

Given that I have already tried reflashing the firmware multiple times without success, can this be definitively confirmed as a hardware fault with the I/O processor or its related circuitry?

Attachments:

A four seconds video is attached in this post.It shows the LED status after connecting to QGC using USB.
Pixhawk6C LED status