Download the Spreadtrum SCI USB2SERIAL Driver (latest version). Extract the files using WinRAR or 7-Zip. 3. Install the Driver

Sometimes, USB 3.0 ports (blue) cause compatibility issues with older Spreadtrum chipsets. Use a instead. 3. Check Cable and Boot Mode

Spreadtrum drivers are not digitally signed by Microsoft. Windows will block them by default.

: Your computer has successfully mapped the device to a Virtual COM Port (e.g., COM3, COM7).

: Click the Start (Play) button in the tool first.

This details will help narrow down the exact boot key combinations and firmware configuration steps required for your scenario. How To Install Spd SCI Usb2Serial Drivers Manually (SciU2S)

Installing a 32-bit (x86) driver on a 64-bit (x64) Windows operating system.

: If you were manually installing via Device Manager , this message indicates that the SCIU2S.INF file was accepted and the hardware is ready to use. Troubleshooting (If "OK" but tool fails)

The message is the gateway to reviving, repairing, and modifying Unisoc-powered devices. It transforms a dead, unrecognized phone into a fully flashable engineering device.

: Professional tools such as SPD Upgrade Tool (ResearchDownload), Infinity-Box CM2SPD, or Miracle Box can now "see" the phone to begin operations.

If your flashing tool does not register the device or throws an error despite attempting an installation, use these troubleshooting steps to resolve the bottleneck: Probable Cause Actionable Solution Yellow triangle icon in Device Manager Driver signature enforcement blocked execution

Because these drivers are older legacy tools, the automatic installer executables often fail. Manual installation guarantees success.

: Install the SCI USB2Serial drivers on your Windows PC.