What was found
EMERGENCY LIGHTS NOT WORKING AT R/H OVERWING HATCHES AND GROUND LIGHT AND INSIDE CABIN BULL NOSE LIGHTS AT ROWS R/H 4, 7, 9, 18, 20, 23, 25 AND L/H ROWS 26 AND 29. GROUNDED - YES. REMOVED AND REPLACED BATTERY PACK AT 7R, 23R AND 28L IAW B737-900 AMM 33-51-06-960-805 RELAMPED R/H AFT OVERWING AND 26R IAW B737-900 AMM 33-51-04-960-801 AND 33-51-03-960-801 OP CHECK GOOD. REPLACED 7R BATTERY PACK P/N D717-01-100 S/N 63539 REPLACED 23R BATTERY PACK P/N D717-01-100 S/N 80647