On a BBU3900, ensure you are plugged into the USB port on the Main Control Board (e.g., UMPT or GTMU). Do not confuse it with the dry contact or transmission ports.
via its USB or maintenance ports from a laptop, you typically need the following: LMT (Local Maintenance Terminal): bbu3900 usb driver
Obtain the driver package (usually provided by Huawei Support or bundled with the LMT software). Connect the USB cable to the UMPT board. On a BBU3900, ensure you are plugged into