Download and install the latest Spreadtrum/Unisoc USB Drivers . Without these, your PC will see the device but won’t be able to "talk" to it. USB Cable: Use a high-quality data cable.
How to Enter Diag Mode on Spreadtrum (SPD) Devices: A Complete Guide enter diag mode spd
Note: This command varies by manufacturer and may require specific property strings like diag,serial_cdev,rmnet,adb 4. Secret Dialer Codes adb 4. Secret Dialer Codes