Re-install your USB drivers and ensure you are using the correct version of the flash tool.
: Always verify your device's exact model number (e.g., C6902 or D5503) in Settings > About Phone
If you encounter difficulties during the installation, consult these common error resolutions:
Flashing will erase everything on your device. If your phone still turns on, back up your photos, contacts, and messages to a cloud service or external drive. Step 2: Install Drivers and Tools
The flashing tool will display a "Flashing Finished" message.Disconnect the USB cable safely from the phone.Press the power button to turn on the device.The initial setup boot may take up to 10 minutes. Troubleshooting Common Flashing Errors
Note that the first boot after flashing can take up to 10 minutes as the system initializes.