The network calibration data (NV RAM network band configuration) may be corrupted along with the serial ID. You will need to flash a complete, working .bin full-flash dump file from a identical working phone before rewriting the identity codes.
Select the platform tab from the chip architecture menu.
: A widely used professional tool for mobile repair. In the interface, you typically use to enable the IMEI options, then navigate to the coolsand rda imei repair tool
: A modern, frequently updated tool that supports a wide range of brands and chipsets, including specialized RDA repair functions. Step-by-Step Repair Process
To better visualize the differences, here is a summary of the major tools available: The network calibration data (NV RAM network band
Power off the device and connect it to the PC. Some devices may require booting into Download Mode (typically by holding Volume UP + Power).
Manually change the boot selection dropdown menu inside your service software (e.g., switching from "RDA8851" to "Coolsand 8809") until you find the configuration that matches your hardware. IMEI Writes Successfully but Still "No Service" : A widely used professional tool for mobile repair
RDA Microelectronics was a prominent Chinese fabless semiconductor company that specialized in designing RF (radio frequency) and mixed-signal semiconductors for cellular, connectivity, and broadcast applications. Coolsand Technologies was another chip designer focused on low-cost 2G and 3G baseband processors.