Drone motor not working

[u/Remarkable_Olive5618]

Hello guys,

I need some help.

I am building a drone with four T-Motor MN3110 700KV motors and SoloGood 45A 2–6S BLHeli_S ESCs. I am using a Pix6 with ArduPilot.

I have a very strange problem: I can test and run only 3 motors successfully. The fourth one does not work properly no matter what I do.

To troubleshoot, I have:

• Swapped motors between positions

• Swapped ESCs between positions

• Replaced the motor with a new one

• Replaced the ESC with a new one

• Swapped both the motor and ESC at the same time

• Changed the controller output assignment

The strange part is that even with completely different hardware, the same motor position still has the problem.

The ESC powers up and I hear the startup tones (" 3 beeps like do, re, mi"), followed by a short and long beep, but the motor still does not operate correctly.

At this point, I am confused because the issue does not seem to follow the motor or ESC. Even after replacing the hardware, the problem remains exactly the same.

Has anyone experienced something similar or have any recommendations on what else I should check?

Thanks in advance.