[beagleboard] BeagleBone won't start when P8_41 and p8_43 are connected to a flip flop

You made a unlucky choice of signals! These pins are also used for system boot strapping (SYS_BOOT*) and must be high-Z at power up.

-- Bas

Be sure and read the System Reference Manual. It helps prevent things like this. Don’t mess with SYSBOOT pins until AFTER the processor boots up.