As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. ON TAKE OFF, ADVANCING THRUST LEVERS TO FLEX DENT, MASTER WARNING LIGHT CAME ON AND MESSAGE "CONFIG PARK BRAKE ON" WARNING. PARKING BRAKE HAD BEEN RELEASED AND THERE WAS NO STATUS MESSAGE. REJECTED TAKEOFF AT ABOUT 50 KTS. NOTIFIED TOWER AND RETURNED TO GATE. MAINTENANCE REPLACED SDAC 2 PER AMM 31-55-34. ACCOMPLISHED SATISFACTORY OPERATIONAL CHECK.