:If the device is powered on and has USB Debugging enabled, you can use the following commands in an ADB terminal: adb shell su setprop sys.usb.config diag,adb Use code with caution. Copied to clipboard
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
Ensure the device's battery sits at a minimum of 30% capacity. If a device drops power mid-operation while in diagnostic mode, it risk corrupting the core partition table. Method 1: The Hardware Boot Key Combination (No Tools) enter diag mode spd
: If Method A fails, hold the Volume Down or Volume Up button (the "Boot Key") while plugging in the cable.
While holding the button, connect the phone to your PC via USB. :If the device is powered on and has
For most modern Unisoc/SPD Android devices, you can enter Diag Mode using a simple USB connection sequence without pressing any hardware buttons: the device completely.
This is the most common way to enter DIAG mode when the device is powered off. the device completely. Press and hold the Volume Up + Volume Down buttons simultaneously. While holding the buttons, connect the device to your PC using a high-quality USB cable. Open a Command Prompt (CMD) and type: adb
Exposing the diagnostic port bypasses standard user-interface restrictions. This gives service tools low-level communication access to the baseband processor:
Diagnostic Mode (Diag Mode) is a hidden protocol built into mobile processors. While Qualcomm devices use Diag mode primarily for CDMA/LTE calibration, uses it to expose a virtual COM port called SPRD U2S Diag . Technicians utilize this mode to repair corrupted IMEI numbers, bypass Factory Reset Protection (FRP), read hardware logs, and fix software bricks. Why Do You Need to Enter SPD Diag Mode?
: Select the brand and model, then choose the "Diag" tab. Follow the on-screen prompts to connect the powered-off device. 3. ADB Command Method (For Rooted/Developer Devices)