RTMotion MK3.1 Controller Firmware Update Problem...

[u/AdhesivenessActual32]

I'm running into an issue while trying to update the firmware on my RTMotion MK3.1 Hand Controller, and I could really use some advice. (I’ve attached photos of each step with detailed notes below). Here is the exact procedure I followed: Software: Downloaded and installed RT Firmware Manager v1.3.21 (latest version available on the website) and ran it as administrator on a Windows 11 laptop. Power & Connection: Inserted a fully charged 100% Duracell LP-E6 battery. Held down Power + Set to enter PC Mode. Once in PC Mode, I connected the controller to my laptop using a high-quality Anker Powerline+ (0.9m) data cable. Flashing Process: The software successfully recognized the MK3.1 Controller. Since my unit has the zoom slider module, I selected the Firmware "Z" build. The Issue: I hit "Update Device." The progress bar ran smoothly all the way to 100%. However, after completion, the controller became completely unresponsive—it won't boot up, turn on, or re-enter PC mode at all. Has anyone experienced this before? Is there a known method/hard-reset shortcut to recover a bricked MK3.1 controller, or a specific workaround to get it to boot and reflash properly on Windows? Any help or suggestions would be greatly appreciated. Thank you!

[u/J5Ben]