What was found
DURING CRUISE, OPEN EMERGENCY DOOR WARNING INDICATION ON EICAS. ACFT RETURN TO DEPARTURE. AT STATION, PERFORMED AMM 52-20-00 OPENED AND CLOSED, APPLIED FIM 52-75-00-810-802-A AND WAS FOUND INDICATION WORKING FINE, PERFORMED CABIN PRESURIZATION LEAKAGE TEST IAW AMM 21-31-00 AND FOUND OK NORMAL. ACFT RETURNED TO NORMAL OPERATION.