: Use an original Samsung USB cable. Switch the device to a different USB port. Check Device Manager to ensure the "SAMSUNG Mobile USB CDC Composite Device" is visible without errors. To help narrow down any issues, let me know: What operating system version are you running?
Always back up your phone’s EFS partition before writing any new data or flashing firmware. Corrupting the EFS partition can permanently destroy the device's network capabilities. Furthermore, changing an IMEI number to a different identity is illegal in many jurisdictions; use the repair features exclusively to restore the device's original factory-printed IMEI number. Z3x Samsung Tool V19.1 Setup
Locate the Samsung_USB_Driver_for_Mobile_Phones.exe file inside the extracted folder. Double-click to launch the installer. : Use an original Samsung USB cable
: Write official stock ROMs, single-file firmware, or multi-file (BL, AP, CP, CSC) packages to revive bricked devices. To help narrow down any issues, let me