What was found
ON PREFLIGHT, FOUND EMERGENCY LIGHTS ILLUMINATED WITH SWITCH IN THE EMERGENCY LIGHTS ARM POSITION. ASSOCIATED CIRCUIT BREAKERS WERE POPPED ON OVERHEAD PANEL. MX REMOVED AND REPLACED BATTERY PACKS B23 AND B24 BEHIND FWD LAV MIRROR. NO HELP. REMOVED AND REPLACED BOTH BATTERY PACKS ON LEFT SIDE OVERWING EXITS. FOUND POWER AT D2 AT S1-177, BUT NO POWER AT D1. REMOVED AND REPLACED S1-177 PER AMM. BOTH CIRCUIT BREAKERS RESET SUCCESSFULLY AFTER COCKPIT SWITCH REPLACEMENT. REPLACED BATTERY PACK B5-40. RELAMPED LT AND RT O/W EMERG LIGHTS AND REPLACED BATTERY IN PACK B5-33. ALL EMERGENCY EXIT LIGHTS OK.