As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMER EXIT LIGHTS ILLUM DURING TAKEOFF ILLUM AT BACK HALF OF CABIN FOR 1 MIN THEN OFF FOUND EMERGENCY BATTERY CHARGER POWER SUPPLY M1673 LEFT SIDE PUSH TO TEST BUTTON BROKEN OFF. REPLACED THE POWER SUPPLY IAW AMM 33-51-06-960-806. OPS CHECK OK ON GROUND.