Ml7820 B Firmware: Link

Even after successful flashing, you may face issues. Here is the expert's checklist:

AT!IMAGE? AT+CGMR AT+CFUN=1 AT+COPS=?

: On Windows, you can find your device's firmware revision by navigating to Device Manager > Properties > Details and selecting "Hardware Ids" from the dropdown. Upgrade Methods Web Management ml7820 b firmware

If the module is completely unresponsive (no USB enumeration, no LED activity), you have two options: Even after successful flashing, you may face issues