IMEI repair is intended for restoring a device to its original factory state using the number printed on the device’s sticker. Changing an IMEI to a different number is illegal in many jurisdictions. Always use the original IMEI associated with the hardware.

If you write the IMEI and it still shows "Invalid," your NVRAM chip might be physically damaged or "Read-Only." Important Legal Notice

Select the RDA tab -> Choose "Write IMEI" -> Input numbers -> Click Start. Pros: High success rate and supports various boot pins. 3. Infinity-Box CM2RDA

If the phone just starts charging when plugged in, you haven't hit the boot key. Common RDA boot keys are the 'Center/OK' button, 'Dial' button, or '*' and '#' together.

If the keypad codes do not work (which happens if the manufacturer has disabled the Engineer Mode), you will need to use a PC-based tool via a USB data cable. 1. RDA Service Tool (Free)

Enter the 15-digit code found under your phone’s battery and hit . Restart the device immediately. Best Software Tools for Coolsand RDA Repair

For many RDA-based feature phones, you can access the engineering or IMEI write menu directly from the keypad.

For professionals, the CM2RDA module is the most stable. It can rebuild the security area of the phone without needing the original backup. Vital Troubleshooting Tips

– (Most Common) This opens the full engineering mode.