What was found
PHX - FLT 0815 - DURING ROUTINE MAINTENANCE CHECK, FOUND EMERGENCY LIGHTS INOP AT LT MID-SHIP. PER T.S.M., REPLACED POWER SUPPLY. FIRST UNIT BAD FROM STOCK AND THEN BATTERY WAS DEAD. SWAPPED BATTERY PACK FROM RT SIDE WITH NEW POWER SUPPLY. LIGHTS OPERATE NORMALLY. MID-LEFT EMERGENCY LIGHT BATTERY, 3214-54. MID-RIGHT EMERGENCY LIGHT BATTERY, 3214-54. MID-RIGHT EMERGENCY LIGHT BATTERY, 3214-54. STC SA 3432NM. REFERENCE OPERATOR CONTROL NR 96ZZZX340, AND NR 96ZZZX341. (X)