When you download the ZIP file with ROM each week, boot (kernel) & system (MIUI/android files) partitions are updated with latest MIUI. However, RADIO* firmware stay the same. Updating RADIO can resolve signal 3G/WiFi sensitivity issues and problems like that. Download the full fastboot ROM at http://en.miui.com/download-37.html by clicking Download Full ROM in Developer section (or better click Flashing Guide in Developer section and then "Xiaomi Mi 2A Latest Developer Version Fastboot File Download"). There are also other fast boot files for older ROMs available at http://en.miui.com/thread-14641-1-1.html Always use fast boot ROM with MIUI version you have installed on your device! Using MiFlash flash the downloaded fast boot ROM in fastboot (use flash_radio.bat script - attached). Done. This procedure will likely work for other devices (Mi2s, Mi3, Mi4 etc). * The RADIO firmware(s) controls basic low-level functions like camera, WiFi or GPS. Some times it is also called modem or baseband (no idea what's the correct term in case of Xiaomi devices).