The modem must be forced into a state where it accepts raw data. This often requires specific "AT Commands" sent through a terminal (like PuTTY or TeraTerm). 2. Backing up the NVRAM
Most L850-GL modules hide the AT command port (COM port) used for low-level access. fibocom l850gl change imei work
Type: AT → You should see OK .
: If the IMEI is lost after a firmware flash, some versions of this modem have no known way to recover it, essentially rendering the cellular functions useless. Step-by-Step Recovery (General Community Guidance) If you are using the tools found on Identify COM Port : Use Device Manager to find the modem's COM port. imei_tool.cmd from the specialized "change IMEI" folders. Input Data : Provide the COM port and the 15-digit IMEI when prompted. Confirm Success The modem must be forced into a state
If you absolutely must change the IMEI for a legitimate engineering purpose (e.g., testing your own network equipment), set up an isolated testing lab with no connection to live carrier networks, and revert the IMEI before deployment. Backing up the NVRAM Most L850-GL modules hide