Modifying IMEI or NVRAM data can be illegal in certain jurisdictions and can brick your device if done incorrectly. Always take a full backup before making changes in Diag Mode.
Keep your Windows Device Manager open to verify the connection. Method 1: The Hardware Key Combination (Most Common)
If you have ADB enabled and the device is rooted, you can force the device into Diag Mode using the command line. Connect your phone to the PC with USB Debugging enabled. Open a Command Prompt (CMD) and type: adb shell su enter diag mode spd
Diagnostic Mode is a special state that allows a computer to communicate directly with the device's modem and internal configuration sectors via a COM port. Unlike "Fastboot" or "Recovery," Diag Mode opens a communication bridge (usually labeled as SPRD U2S Diag in Device Manager) that lets service software read and write sensitive data required for network connectivity and hardware identification. Prerequisites before Starting
If you are working with a smartphone powered by a Spreadtrum (now Unisoc) chipset, you’ve likely encountered the need to enter (Diagnostic Mode). Whether you are trying to repair an IMEI, back up your NVRAM data, or perform deep system repairs using tools like Pandora, CM2, or Research Download, Diag Mode is the gateway you need. Modifying IMEI or NVRAM data can be illegal
Once granted root access, enter: setprop sys.usb.config diag,adb
This is a driver issue. Right-click the unknown device, select "Update Driver," and manually point to the folder where you extracted your Spreadtrum drivers. 3. Phone Just Charges Method 1: The Hardware Key Combination (Most Common)
Entering Diag Mode on a Spreadtrum device is the first step toward advanced mobile repair. While the method works for 80% of devices, knowing the Dialer Codes and ADB commands ensures you can handle any situation.
Check Device Manager under . You should see "SPRD U2S Diag" or "Unisoc Diagnostics Port." Method 2: Using Secret Dialer Codes
The phone should instantly switch ports in your Device Manager. Method 4: Using Professional Service Tools