How to fix not working Wi-Fi on Xiaomi Mi 5S

Recently we’ve been reported that some users have issues with not working WiFi on Xiaomi Mi5S. This issue may appear after you’ve flashed Custom ROM on your phone for the first time. Here’s the solution that we’ve recently tested. Hope it will help you to restore WiFi connection on your device as well!

[Solution] Can’t connect to WiFi on Xiaomi Mi5S

For this method you’ll require to have superuser permission enabled on your phone. Will also work on Xiaomi Mi5 with Custom ROM.

The issue is result of a broken MAC-address, which shows in red color in engineering menu.

1. Install ADB driver on your PC.
2. Flash your MIUI smartphone.
3. Enable developer options.
4. Then go to “Developer options” and enable “USB-debugging”.
5. Go to the folder with ADB files and press “Shift” + Right Mouse button at empty space, then select “Open command window here”.
6. Type the following commands in terminal window:

   adb devices
   adb shell
   su
   cd /persist/
   mv wlan_bt wlan_bt_bak
   mv wlan_mac.bin wlan_mac.bak

7. After this make the factory reset of your phone and use clean MIUI firmware.
8. WiFi connection should work now.

Original source: https://forum.xda-developers.com/general/help/connect-to-wifi-installing-cm-13-xiaomi-t3532137

Second method:

If the method above didn’t worked for you, try the solution below and then repeat the above steps. This will help to restore the modem after flashing.

• Must have unlocked bootloader.
• Remove SIM-card before following this method.

What’s required:

1. Download and install ADB drivers.
2. Copy NON-HLOS.bin file from the currently installed ROM (you can find it here /firmware-update/NON-HLOS.bin).
3. Backup modemst1, modemst2, fsg partitions (root is required).
4. Open command window from the folder with ADB files and type the following commands (backup files will be created in phone memory):

   adb shell 
   su 
   dd if=/dev/block/sde28 of=/sdcard/modemst1 
   dd if=/dev/block/sdf3 of=/sdcard/modemst2 
   dd if=/dev/block/sdf5 of=/sdcard/fsg

5. Installed SuperSU.

Now let’s start with the tutorial:

1. Connect your phone to PC.
2. Flash NON-HLOS.bin file. Copy “NON-HLOS.bin” to the folder with ADB files, open the command window and use the following commands:

   fastboot devices
   fastboot.exe erase modem
   fastboot.exe flash modem NON-HLOS.bin
   fastboot.exe reboot

3. Your phone will reboot. Now wipe the required partitions. Use the following commands:

   adb shell
   su
   dd if=/dev/zero of=/dev/block/sde28
   dd if=/dev/zero of=/dev/block/sdf3
   reboot

4. Your phone will reboots.
5. Modem should be restored now. To fix not working Wi-Fi you can try to repeat the steps above.