# Forcing the KX3 into "Firmware Load Required" Mode

To force the KX3 into a state that it requires a firmware download,

- Switch off the power supply or disconnect the KX3 from its power supply and batteries for at least 30 seconds. The KX3 microcontroller may continue to function with very low voltage, the current draw is quite low, capacitors take a while to discharge, and the MCU must perform a power-on reset to enter its bootstrap loader.
- Click Close Port.
- Reconnect the power supply.
- Press and hold the two KX3 power-on buttons (BAND- and ATU TUNE) for about 10 seconds until the red TX LED begins to blink and "MCU LD" appears in the LCD display. The LCD back light may be off.
- Click Test Communications. You should see a status message indicating that the KX3 is ready for MCU firmware load.
- Select Send All Firmware on the Firmware tab.