What was found
AFTER DEPARTING CVG IN HEAVY RAIN, ESSENTIAL POWER WARNING LIGHT STARTED TO PARTIALLY ILLUMINATE FOLLOWED BY ALL 3 REVERSER LIGHTS, THEN GEAR LIGHTS. NO OTHER INDICATIONS OF ACTUAL PROBLEMS THOUGH. CYCLED WARNING LIGHTS TEST SWITCH TO BRIGHT AND LIGHTS WENT OUT. THEN CYCLED TEST SWITCH BACK TO DIM AND ALL LIGHTS CONNECTED WITH THAT TEST SWITCH ILLUMINATED AND STAYED ON. UNABLE TO GET LIGHTS TO GO OUT AFTER. CONFIRMED NR 2 THRUST REVERSER ANNUNCIATOR INTERNALLY SHORTED. REPLACED SAME. ALL INSTRUMENT PANEL ANNUNCIATORS CHECK GOOD IAW B727 M/M 33-10-41. ANNUNCIATOR REPLACEMENT DONE IAW B727 M/M 33-10-51.