# Key Combos There are times when your flipper feels blue and doesn't respond to your commands. In that case, you may find this guide useful. ## Basic Combos ### Hardware Reset - Press `LEFT` and `BACK` and hold for a couple of seconds - Release `LEFT` and `BACK` This combo performs hardware reset by pulling MCU reset line down. Main components involved: Keys -> DD8(NC7SZ32M5X, OR-gate) -> DD1(STM32WB55, MCU) There is 1 case when it's not working: - MCU debug block is active and holding reset line from inside. ### Hardware Power Reset - Disconnect USB and any external power supplies - Disconnect USB once again - Make sure that you've disconnected USB and any external power supplies - Press `BACK` and hold for 30 seconds (Only will work with USB Disconnected) - If you have not disconnected USB, then disconnect USB and repeat previous step - Release `BACK` key This combo performs a reset by switching SYS power line off and then on. Main components involved: Keys -> DD6(bq25896, charger) There is 1 case when it's not working: - Power supply is connected to USB or 5V_ext ### Software DFU - Press `LEFT` on boot to enter DFU with flipper boot-loader There is 1 case when it's not working: - Flipper Boot-loader is damaged or absent ### Hardware DFU - Press `OK` on boot to enter DFU with ST boot-loader There is 1 case when it's not working: - Option Bytes are damaged or set to ignore `OK` key ## DFU Combos ### Hardware Reset + Software DFU - Press `LEFT` and `BACK` and hold for a couple of seconds - Release `BACK` - Device will enter DFU with indication (Blue LED + DFU Screen) - Release `LEFT` This combo performs hardware reset by pulling MCU reset line down. Then `LEFT` key indicates to boot-loader that DFU mode is requested. There are 2 cases when it's not working: - MCU debug block is active and holding reset line from inside - Flipper Boot-loader is damaged or absent ### Hardware Reset + Hardware DFU - Press `LEFT` and `BACK` and `OK` and hold for a couple of seconds - Release `BACK` and `LEFT` - Device will enter DFU without indication This combo performs hardware reset by pulling MCU reset line down. Then `OK` key forces MCU to load internal boot-loader. There are 2 cases when it's not working: - MCU debug block is active and holding reset line from inside - Option Bytes are damaged or set to ignore `OK` key ### Hardware Power Reset + Software DFU - Disconnect USB and any external power supplies - Press `BACK` and `LEFT` for 30 seconds - Release `BACK` - Device will enter DFU with indication (Blue LED + DFU Screen) - Release `LEFT` - Plug USB This combo performs reset by switching SYS power line off and then on. Then `LEFT` key indicates to boot-loader that DFU mode requested. There are 2 cases when it's not working: - Power supply is connected to USB or 5V_ext - Flipper Boot-loader is damaged or absent ### Hardware Power Reset + Hardware DFU - Disconnect USB and any external power supplies - Press `BACK` and `OK` and hold for 30 seconds - Release `BACK` and `OK` - Device will enter DFU without indication - Plug USB This combo performs reset by switching SYS power line off and then on. Then `OK` key forces MCU to load internal boot-loader. There are 2 cases when it's not working: - Power supply is connected to USB or 5V_ext - Option Bytes are damaged or set to ignore `OK` key # Alternative ways to recover your device If none of the described methods were useful: - Ensure the battery charged - Disconnect the battery and connect again (Requires disassembly) - Try to Flash device with ST-Link or other programmer that supports SWD If you still here and your device is not working: it's not a software issue.