Install your flashing box drivers. If you see "Unknown Device" in Device Manager, you cannot proceed.
A high-quality micro-USB cable for a stable connection.
: For official hardware issues, you can locate a Samsung Service Center or use their Remote Service options.
If you are a repair shop, memorizing the samsung e2252 flash tool 1000 ok procedure is a monthly revenue generator. For individuals, it is the difference between e-waste and a reliable work phone.