unleashed-firmware/documentation/KeyCombo.md

Key Combos

There are times when your Flipper feels blue and doesn't respond to any of your commands due to a software issue. This guide will help you solve this problem.

Basic combos

Hardware reset

• Press LEFT and BACK and hold for a couple of seconds
• Release LEFT and BACK

This combo performs a hardware reset by pulling the MCU reset line down. Main components involved: Keys -> DD8(NC7SZ32M5X, OR-gate) -> DD1(STM32WB55, MCU).

It won't work only in one case:

• The MCU debug block is active and holding the reset line from inside.

Hardware Power Reset

• Disconnect the USB cable and any external power supplies
• Disconnect the USB once again
• Make sure you've disconnected the USB and any external power supplies
• Press BACK and hold for 30 seconds (this will only work with the USB disconnected)
• If you haven't disconnected the USB, then disconnect it and repeat the previous step
• Release the BACK key

This combo performs a reset by switching SYS power line off and then on. Main components involved: Keys -> DD6(bq25896, charger).

It won't work only in one case:

• Power supply is connected to USB or 5V_ext

Software DFU

• Press LEFT on boot to enter DFU with Flipper boot-loader

It won't work only in one case:

• Flipper boot-loader is damaged or absent

Hardware DFU

• Press OK on boot to enter DFU with ST boot-loader

It won't work only in one case:

• Option Bytes are damaged or set to ignore the 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 an indication (Blue LED + DFU Screen)
• Release LEFT

This combo performs a hardware reset by pulling the MCU reset line down. Then, the LEFT key indicates to the boot-loader that DFU mode is requested.

It won't work in two cases:

• The MCU debug block is active and holding the reset line from inside
• Flipper boot-loader is damaged or absent

Hardware Reset + Hardware DFU

• Press LEFT, BACK and OK and hold for a couple of seconds
• Release BACK and LEFT
• The device will enter DFU without an indication

This combo performs a hardware reset by pulling the MCU reset line down. Then, the OK key forces MCU to load the internal boot-loader.

It won't work in two cases:

• The MCU debug block is active and holding the reset line from inside
• Option Bytes are damaged or set to ignore the OK key

Hardware Power Reset + Software DFU

• Disconnect the USB and any external power supplies
• Press BACK and LEFT for 30 seconds
• Release BACK
• The device will enter DFU with an indication (Blue LED + DFU Screen)
• Release LEFT
• Plug in the USB

This combo performs a reset by switching the SYS power line off and then on. Next, the LEFT key indicates to the boot-loader that DFU mode is requested.

It won't work in two cases:

• Power supply is connected to USB or 5V_ext
• Flipper boot-loader is damaged or absent

Hardware Power Reset + Hardware DFU

• Disconnect the USB and any external power supplies
• Press BACK and OK and hold for 30 seconds
• Release BACK and OK
• The device will enter DFU without indication
• Plug in the USB

This combo performs a reset by switching the SYS power line off and then on. Next, the OK key forces MCU to load the internal boot-loader.

It won't work in two cases:

• Power supply is connected to USB or 5V_ext
• Option Bytes are damaged or set to ignore the OK key

Alternative ways to recover your device

If none of the described methods helped you:

• Make sure the battery charged
• Disconnect the battery and connect again (requires disassembly)
• Try to flash the device with ST-Link or another programmer that supports SWD

If you're still here and your device is not working: it's not a software issue.