What was found
ENROUTE FROM JAX TO CLT, CREW REPORTED THE AIRCRAFT LIGHT TEST SYSTEM WENT INTO PARTIAL TEST MODE WITH HALF THE TEST LIGHTS ILLUMINATING, INCLUDING FIRE HANDLES. FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE MASTER TEST RELAY R33, PIN D1, POWERED AT ALL TIMES. TROUBLESHOT TO P5-4 MODULE, PIN 3 TO PIN 10 OF D634, SHORTED. REMOVED AND REPLACED THE P5-4 MODULE PER MM 24-21-51-4. SYSTEM OPERATIONALLY CHECKS NORMAL.