Get the latest USB_Driver_for_Huawei.zip from Huawei’s support page.
For hard-bricked devices (black screen, no vibration, no fastboot), you need Test Point (TP) mode. This shorts two specific pins on the motherboard to force the CPU into "Download Mode." huawei kirin usb driver
How the driver helps here:
Once you short the Test Point and connect the phone to the PC, the device appears as Huawei USB COM 1.0 (COM 3) in Device Manager. Without the Kirin USB driver, it shows as "Unknown Device." With the driver, IDT (Image Download Tool) can flash a fresh bootloader. Get the latest USB_Driver_for_Huawei
Note: This requires opening the phone's casing and voiding the warranty. Only for experts. Alternatively, run the DriverSetup
Alternatively, run the DriverSetup.exe if included in the package.