What was found
EMERGENCY LIGHTS ON CENTER ROW 48-52 BOTH SIDES INOPERATIVE. REMOTE WELS CONTROL UNIT LAMP DRIVER POWER CIRCUIT IS FAILED. PERFORMED FIM B787-A-33-50-F1-E9A-421A-A. SWAPPED WELS CONTROL UNIT #29 WITH NEW CONTROL UNIT IAW AMM B787-A-33-51-07-01A-520A-A AND B787-A-33-51-07-01A-720A-A. FAULT STILL PERSISTED. REINSTALLED ORIGINAL WELS CONTROL UNIT CLASS 29. RELAMPED FLOOR PROXIMITY LIGHTS AT SEATS 52D AND 52F REF AMM 33-51-06. AFTER RELAMPING, ALL FLOOR PROXIMITY LIGHTS BETWEEN ROWS 48 AND 52 OPERATE AS REQUIRED.