As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF ROLL AT LAS EN ROUTE FOR JFK THE TOWER ADVISED FLIGHT CREW A PANEL WAS OPEN, TAKEOFF WAS REJECTED AT LOW SPEED. TAXIED BACK TO RAMP AND MAINTENANCE SECURED THE FORWARD GROUND POWER PANEL. TAXIED BACK TO RUNWAY, DEPARTED WITHOUT FURTHER EVENT.