Momentum-Apps/documentation/KeyCombo.md

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

There is 1 case where it does not work:

• 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 (Will only 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 where it does not work:

• 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 where it does not work:

• Flipper boot-loader is damaged or absent

Hardware DFU

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

There is 1 case where it does not work:

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

There are 2 cases where it does not work:

• MCU debug block is active and holding 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
• Device will enter DFU without indication

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

There are 2 cases where it does not work:

• 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 in USB

This combo performs a 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 where it does not work:

• 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 a reset by switching SYS power line off and then on. Then, OK key forces MCU to load internal boot-loader.

There are 2 cases where it does not work:

• 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 are here and your device is not working: it's not a software issue.