*#3646633# – The primary RDA/Coolsand engineering mode access code.
If your device still shows "Invalid IMEI" after these steps, you may need to reload the stock operating system or visit a professional service center.
The codes might not be activating because the firmware is locked. You may need to flash the phone with a new dump file. coolsand rda imei repair code best
These codes are effective but often depend on the specific firmware version of the device. The Most Common RDA IMEI Method: Open the Dialer/Keypad.
Press and hold the on the handset—on most Coolsand devices, this is the "0" key , the Green Call key , or the Central OK button . You may need to flash the phone with a new dump file
Click the Start/Write button on the software and quickly plug in the USB cable (you may need to hold the center button, *, or 0 key). Complete: The tool will show a "Done" or "Passed" message. Verify: Disconnect the phone, turn it on, and dial to verify the new IMEI. Troubleshooting: Why Codes Don't Work
Furthermore, if you are using the , the command line method is considered the best RDA IMEI repair code : Press and hold the on the handset—on most
Click or Write . The software will scan the flash sectors, rebuild the binary structure, and output a "Write Completed" or "Done" log.
Try these codes first by opening your phone’s dialer and typing them exactly as shown:
If you successfully enter the Engineering Mode menu using a code above, follow these steps: Navigate to the or GPRS tab. Select IMEI or Write IMEI .