Replace the USB cable with an original high-quality lead, use a rear motherboard USB port if using a desktop PC, and check Device Manager to verify the phone is listed under "Modems" or "Android Device". Safety and Compliance Notice
The Z3x software cannot communicate with a mobile device without the proper interface bridges. Samsung USB Drivers Z3x Samsung Tool 29.5 Setup
What are you trying to accomplish (flashing, unlocking, or repair)? Replace the USB cable with an original high-quality
Download the official Z3x Samsung Tool 29.5 Setup from the manufacturer’s website (z3x-team.com) or trusted resellers. Avoid cracked or modified versions as they may contain malware or cause permanent device damage. Z3x Samsung Tool 29.5 Setup