| Problem | Solution | |--------|----------| | Black screen on boot | Add nomodeset to GRUB boot parameters. | | Wi-Fi not working | Use an external USB Wi-Fi dongle (Realtek chipset). Try modprobe wl in terminal. | | Play Store error DF-DFERH-01 | Delete your Google account, clear Google Play Services data, reboot, re-add. | | No sound from headphones | Install “Sound About” app to manually route audio. | | Can’t resize window | Enable “Force activities to be resizable” in Developer Options. |