Download SPD USB Drivers (Spreadtrum/Unisoc) v4.21.39.134 - Latest 2026
Download SPD USB Drivers (Spreadtrum/Unisoc) Latest Version 2026
If you own a device powered by a Spreadtrum (now Unisoc) processor, you already know that working with these phones requires a specific set of USB drivers. Brands like Infinix, Tecno, Itel, Samsung (some entry-level models), Xiaomi (low-end devices), and many Chinese tablet manufacturers use SPD/Unisoc chipsets. Without the correct drivers, your PC simply will not detect your device, and tools like SPD Research Download Tool, SPD Upgrade Tool, or WriteIMEI Tool will fail to connect.
The latest SPD USB Driver v4.2 (also known as Spreadtrum SCI USB2Serial Driver or Spreadtrum Jungo Driver) is the essential bridge between your Windows PC and any device running on Unisoc/Spreadtrum chipsets including Unisoc T820, T616, T606, T612, T615, T620, T760, T765, T7200, T7225, T7250, T7280, T8100, T8200, T8300, T9100, Spreadtrum SC9863, SC6531, and older SC77xx series.
In this comprehensive guide, I will provide you with the latest free download links for both Spreadtrum Jungo Driver and Spreadtrum SCI Driver, complete step-by-step installation instructions for Windows 11/10/8/7, and a detailed troubleshooting section to fix common detection issues.
Table of Contents
- Download SPD USB Drivers (Spreadtrum/Unisoc) Latest Version 2026
- Table of Contents
- Why SPD USB Drivers Are Essential
- SPD Driver Types Explained
- Supported Devices and Processors
- Check Requirements Before Download
- How to Install SPD USB Driver v4.21.39.134 on Windows
- Essential Troubleshooting for SPD Driver Issues
- Download SPD USB Drivers v4.2
- Conclusion
- Frequently Asked Questions
- This Article Solves Following High-Value Search Queries
Why SPD USB Drivers Are Essential
Unlike MediaTek devices that use PreLoader VCOM mode or Qualcomm devices that use QDLoader 9008 mode, Spreadtrum and Unisoc devices have their own unique communication protocol. The SPD USB drivers enable your Windows PC to communicate with your phone in SCI USB2Serial Mode.
Key Operations Enabled by SPD Drivers
- Firmware Flashing: Using SPD Research Download Tool or SPD Upgrade Tool to flash stock firmware (
.pacfiles) on bricked devices - IMEI Repair: Using WriteIMEI Tool to repair lost or corrupted IMEI numbers
- FRP Bypass: Removing Factory Reset Protection on locked devices
- System Recovery: Rescuing devices stuck in boot loops or soft bricked
- NVRAM Backup/Restore: Backing up critical device calibration data
How SPD Connection Works
When you connect a powered-off Spreadtrum/Unisoc device to your PC, it briefly enters SCI USB2Serial mode. The correct SPD driver allows Windows to recognize this connection and assign a COM port. Without the driver, your device will appear as “Unknown Device” or not appear at all in Device Manager.
SPD Driver Types Explained
There are two main types of SPD USB drivers you will encounter. Both are included in our download package.
| Driver Type | File Name | Size | Primary Use |
|---|---|---|---|
| Spreadtrum Jungo Driver | SPRD_Unisoc_v4.21.39.134_GSM6.com.zip | 8.24 MB | General flashing and IMEI writing; works with most SPD Flash Tools |
| Spreadtrum SCI Driver | SPRD_Unisoc_v4.21.39.134_GSM6.com.zip | 8.24 MB | Alternative driver for specific chipsets; often required for older devices |
Which one should you install? File contains Both, it will install automatically no need separate installation. The Jungo driver works for most modern Unisoc devices (T-series), while the SCI driver is sometimes required for older Spreadtrum SC-series chipsets. Having both installed ensures compatibility across all devices.
Supported Devices and Processors
Supported Processor Families
| Brand | Chipset Series |
|---|---|
| Unisoc (Modern) | T820, T616, T606, T612, T615, T620, T760, T765, T7200, T7225, T7250, T7280, T8100, T8200, T8300, T9100 |
| Spreadtrum (Legacy) | SC9863, SC9832, SC7731, SC6531, SC77xx, SC88xx, SC98xx |
| Other | Tiger series, Shark series, UIS series |
Popular Phone Models with SPD/Unisoc Chipsets
| Brand | Models |
|---|---|
| Infinix | Smart series (Smart 6, Smart 7, Smart 8), Hot 10 Play, Hot 11 Play (SPD variants) |
| Tecno | Pop series, Spark Go series, TECNO POP 5, TECNO POP 6 |
| Itel | A series (A16, A23, A25, A26), P series (P11, P12, P13, P17) |
| Samsung | Galaxy A03 Core, Galaxy A04e (some variants), Galaxy A12 (some variants) |
| Xiaomi | Redmi 6A (SPD variant), Redmi 7A (selected markets), POCO C3 (some variants) |
| Realme | Realme C2 (SPD variant), Realme C11 (selected markets) |
| Nokia | Nokia C1, Nokia C2, Nokia C3 |
| Alcatel | 1 series, 3 series (entry-level variants) |
Note: Many low-end and budget smartphones from Transsion brands (Infinix, Tecno, Itel) use SPD/Unisoc processors. Always verify your device’s chipset before proceeding.
Check Requirements Before Download
Before you begin the installation, here are the key details about the latest driver version.
| Specification | Details |
|---|---|
| Driver Name | SPD USB Driver (Spreadtrum/Unisoc) |
| Version | v4.21.39.134 |
| Supported OS | Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 11 (32-bit & 64-bit) |
| File Size | 8.24 MB |
| Format | ZIP Archive |
| Installation Method | Manual via Device Manager |
| Driver Signature | Unsigned (requires disabled enforcement) |
| Release Date | April 2026 |
| Price | Free |
How to Install SPD USB Driver v4.21.39.134 on Windows
Unlike MediaTek drivers which have an auto-installer, SPD drivers must be installed manually through Device Manager. Follow these steps carefully.
Step 1: Disable Driver Signature Enforcement
SPD drivers are not digitally signed by Microsoft. Windows 8, 10, and 11 will block them by default. You must disable driver signature enforcement temporarily.
Method 1: Using Advanced Startup (Windows 10/11)
- Click Start → Settings → Update & Security → Recovery
- Under “Advanced startup”, click Restart now
- After restart, click Troubleshoot → Advanced options → Startup Settings → Restart
- When the Startup Settings screen appears, press 7 or F7 to select “Disable driver signature enforcement”
- Your PC will restart. Login normally.
Method 2: Using Command Prompt (All Windows Versions)
Open Command Prompt as Administrator and run the following command: ‘bcdedit /set {current} testsigning on’
Restart your PC. You will see “Test Mode” watermark in the corner. After driver installation, disable test mode with this command: ‘bcdedit /set {current} testsigning off’
Step 2: Download and Extract the Driver Package
- Download the SPD USB Driver package from the link below
- Right-click the ZIP file and select Extract All
- Extract to a folder you can easily access (e.g., Desktop)
Step 3: Manual Installation via Device Manager
Install Spreadtrum Jungo Driver:
Open Device Manager (Press
Win + Xand select Device Manager, or typedevmgmt.mscin Run)Click on your computer name at the top of the list
From the Action menu, select Add legacy hardware
Click Next on the Hardware Installation Wizard
Select Install the hardware that I manually select from a list (Advanced) and click Next
Scroll down and select Show All Devices, then click Next
Click Have Disk
Click Browse and navigate to the extracted
Spreadtrum_Jungo_USB2SerialfolderInside, go to
x64(for 64-bit Windows) orx86(for 32-bit Windows), then open thedriverfolderSelect the
Spreadtrum_Jungo.inffile and click Open, then OKClick Next then Next again to install
You may see a warning that the driver is not digitally signed. Click Install this driver software anyway or Yes
Click Finish when complete
Install Spreadtrum SCI Driver (Optional but Recommended):
Repeat the same steps using the Spreadtrum_SCI_USB2Serial folder and select SciU2S.inf as the driver file.
Step 4: Verify Installation
After installation, in Device Manager:
- Expand Ports (COM & LPT)
- You should see SPD USB2Serial or SCI USB2Serial with a COM port number
You may see a yellow exclamation mark (Code 10) if the driver is unsigned. This is normal and the driver will still work. Ignore it and proceed with your flashing tasks.
Essential Troubleshooting for SPD Driver Issues
Even with the correct drivers, you might run into common issues. Here is a complete troubleshooting guide.
SPD Driver Installation Troubleshooting Table
| Problem | Symptoms | Solution |
|---|---|---|
| Driver Install Fails | ”Driver is not digitally signed” popup | Disable driver signature enforcement (Step 1 above) |
| No COM Port Detected | Device not showing in SPD Flash Tool | Ensure phone is powered OFF. Try holding Volume Down while connecting. Use USB 2.0 port, not USB 3.0 |
| Code 10 Error | Yellow exclamation mark in Device Manager | This is normal for unsigned drivers. The driver will still work. Ignore and proceed |
| Unknown Device | Shows as “Unknown Device” or “USB Device not recognized” | Uninstall all existing SPD drivers using USBDeview, restart PC, reinstall manually |
| Connection Drops | Flash process starts then stops | Use high-quality USB cable. Connect directly to motherboard USB port (back of desktop PC, not front panel) |
| SCI Driver Not Working | Jungo driver works but SCI fails | You don’t need both. Use Jungo driver only for most devices |
| Phone Not Entering SCI Mode | PC makes no sound when connecting | Phone battery may be dead. Charge phone for 30 minutes before attempting. Remove battery (if removable) and reconnect |
| Vendor ID Not Detected | ”No device found” in WriteIMEI Tool | Add USB Vendor ID manually: Go to adb_usb.ini file location and add 0x1782 (Spreadtrum Vendor ID) on a new line |
| Tool Crashes on Connect | SPD Research Tool closes immediately | Run the tool as Administrator. Disable antivirus temporarily |
| Windows 11 Error | Driver blocked by Windows Security | Disable Memory Integrity in Windows Security → Device Security → Core Isolation → Memory Integrity → OFF |
Common SPD Flash Tool Errors and Fixes
| Error Code | Message | Solution |
|---|---|---|
| Error 0x7D4 | S_BROM_DOWNLOAD_DA_FAIL | Driver issue. Reinstall SPD drivers completely, disable driver signature enforcement |
| Error 0x4BE | BROM ERROR: S_FT_ENABLE_DRAM_FAIL | Wrong firmware for your device. Download correct stock ROM for your exact model |
| Error 0xFC6 | Download fails at 10% | Bad USB cable. Try a different cable. Use USB 2.0 port only |
| Error 0xFD0 | Packet load failed | Corrupted firmware file (.pac). Re-download firmware from reliable source |
| Error 0x1208 | Handshake failed | Phone not in SCI mode. Power off completely, hold Volume Down while connecting |
Download SPD USB Drivers v4.2
Here are the official download links for the complete SPD USB Driver package. Both Jungo and SCI drivers are included.
SPD USB Driver Specifications
| Specification | Details |
|---|---|
| Driver Name | SPD USB Driver (Spreadtrum/Unisoc) |
| Version | v4.21.39.134 |
| Supported OS | Windows 7 / 8 / 10 / 11 (32-bit & 64-bit) |
| File Size | 8.24 |
| Format | ZIP Archive |
| Installation | Manual via Device Manager |
| Release Date | April 2026 |
| Price | Free |
Download Options
| Link Type | Format | Size | Download Link |
|---|---|---|---|
| Direct Link - Recommended | ZIP | 8.24 MB | Download SPD/Unisoc Driver v4.21.39.134 |
| Mirror Link - G-Drive | ZIP | 8.24 MB | Download SPD/Unisoc Driver v4.21.39.134 |
Security Check: Always verify downloaded files are intact. Use antivirus scan before extraction.
Conclusion
Installing the correct SPD USB drivers is the most fundamental step when working with any Spreadtrum or Unisoc powered device. Unlike MediaTek drivers that come with an auto-installer, SPD drivers require a manual installation process through Device Manager.
The key points to remember:
- Always disable driver signature enforcement on Windows 8/10/11 before installation
- Install both Jungo and SCI drivers for maximum compatibility across different chipsets
- Code 10 errors are normal for unsigned drivers and can be safely ignored
- Use USB 2.0 ports for best compatibility with SPD devices
- Keep the phone powered OFF when connecting for flashing
With these drivers properly installed, you will be able to flash firmware using SPD Research Download Tool, repair IMEI using WriteIMEI Tool, and recover bricked devices. For any further questions or assistance, leave a comment below.
Tags: #SPDDrivers #Spreadtrum #Unisoc #SCIDriver #USBDrivers #SPDFlashtool #AndroidRepair #GSM6
Frequently Asked Questions
Q1: What is the difference between Spreadtrum Jungo Driver and SCI Driver?
The Jungo driver is the primary driver for most modern Unisoc devices. The SCI driver is an alternative that works on some older Spreadtrum chipsets and specific device variants. Install both for complete compatibility. zip file contains both
Q2: Why do I need to disable driver signature enforcement?
SPD drivers are not digitally signed by Microsoft. Windows 8, 10, and 11 block unsigned drivers by default. Disabling signature enforcement temporarily allows you to install these drivers.
Q3: Is it safe to disable driver signature enforcement?
Yes, it is safe to disable temporarily. The setting only applies for one boot session on Windows 8/10/11 (using Advanced Startup method). When you restart normally, signature enforcement is re-enabled.
Q4: Why does my driver show Code 10 error in Device Manager?
Code 10 error appears because the driver is unsigned. Windows is warning you that the driver publisher cannot be verified. The driver will still work for flashing purposes. Ignore this error.
Q5: Do these drivers work on Windows 11?
Yes. The v4.2 drivers work on Windows 11 64-bit. You must disable driver signature enforcement using the Advanced Startup method before installation.
Q6: My phone is not detected even after driver installation. What do I do?
Try these steps in order:
- Power off phone completely (not just screen off)
- Hold Volume Down button while connecting USB cable
- Use a USB 2.0 port (not USB 3.0)
- Try a different USB cable
- Remove battery (if removable) and reconnect
Q7: What is the USB Vendor ID for Spreadtrum devices?
The USB Vendor ID for Spreadtrum/Unisoc is 0x1782. Some tools (like WriteIMEI Tool) require you to add this to the adb_usb.ini file for proper detection.
Q8: Can I use these drivers for Qualcomm or MediaTek devices?
No. SPD drivers ONLY work for Spreadtrum and Unisoc chipsets. For MediaTek devices, download MTK USB Drivers. For Qualcomm devices, download Qualcomm USB Drivers from GSM6.com.
Q9: Why does my phone only stay connected for 2 seconds?
This is normal behavior. SPD devices enter SCI mode temporarily when powered off and connected. The flashing tool must start the process within that window. Make sure your tool is ready and click “Download” or “Start” BEFORE connecting the phone.
Q10: Do I need both 32-bit and 64-bit drivers?
The driver packages contain both x86 (32-bit) and x64 (64-bit) driver files. Choose the folder matching your Windows architecture. Most modern PCs use 64-bit Windows.
Q11: What tools require these SPD drivers?
- SPD Research Download Tool (firmware flashing)
- SPD Upgrade Tool (.pac firmware flashing)
- WriteIMEI Tool (IMEI repair)
- Miracle Box (SPD module)
- CM2 SPD Tool
Q12: Will these drivers work on Mac or Linux?
No. These drivers are designed for Windows only. Mac and Linux users can use virtual machines (VMware, VirtualBox) with Windows installed to use SPD flashing tools.
Q13: I installed the drivers but SPD Flash Tool still says “No Device”. What now?
- Run the flashing tool as Administrator
- Try a different order: Open tool → Load firmware → Click “Download” → THEN connect powered-off phone
- Try holding Volume Up or Volume Down while connecting
- Disable antivirus temporarily (some antivirus blocks low-level USB communication)
Q14: What is the latest version of SPD drivers?
As of April 2026, v4.21.39.134 is the latest stable release. This version includes improved Windows 11 compatibility.
Q15: Can I install these drivers on Windows 7?
Yes. Windows 7 does not enforce driver signature as strictly as newer Windows versions. The manual installation steps are the same.
This Article Solves Following High-Value Search Queries
- Download SPD USB Driver for Windows 11
- Spreadtrum SCI USB2Serial driver download
- Unisoc USB driver installation guide
- SCI driver Code 10 error fix
- SPD driver not detecting phone solution
- Spreadtrum Jungo driver download
- How to install Spreadtrum USB driver manually
- SPD Research Download Tool driver issue
- WriteIMEI Tool no device fix
- Unisoc T606 driver download
- Spreadtrum SC9863 USB driver
- SPD driver signature enforcement bypass
- Windows 10/11 SPD driver installation
- Transsion SPD device driver
- Infinix SPD USB driver
Author:
Abdul MalikMobile Software Expert and founder of GSM6.com. Specializes in FRP bypass, IMEI repair, and advanced mobile tools. All tutorials are tested on real devices for accuracy and safety.
