As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE EMERGENCY EXIT LIGHT TEST DOES NOT WORK. TESTED THE AUTONOMOUS UNIT AND ONLY THE NR2 BATTERY RED LIGHT CAME ON. R & R THE NR 2 BATTERY AND THEN NO TEST LIGHTS WOULD COME ON. R & R THE AUTONOMOUS UNIT IAW MM 52-73-18-04. OPS CHECKED IAW MM 52-73-00-05-01 AND MM 33-51-00-05. OPS CHECKED NORMAL. OK FOR SERVICE.