Bootloader mode is indicated by a continually repeating series of pulses on the bottom row of I/O LEDs. Double-clicking the reset button puts the ClearCore into bootloader mode.
USB connected: The I/O LEDs IO-5 through IO-0 flash from right to left and the UnderGlow LED is breathing.
No USB connected: The I/O LEDs IO-0 through IO-5 flash from left to right and the UnderGlow LED is off.