What was found
RETURNED, ACFT WAS NOT GNDED. CLIMBING THROUGH 1500" FLIGHT CREW RECEIVED EICAS MSG, DOOR EMER LT OPEN. FLIGHT CREW DECLARED AN EMER & RETURNED, WHERE THE ACFT LANDED WITHOUT FURTHER INCIDENT. MSG EXTINGUISHED AFTER LANDING. VENT FLAP FOUND PARTIALLY OPEN UPON ARRIVAL AT GATE. REMOVED OVERWING HATCH. INSPECTED S327, WARNING SWITCH & DOOR HANDLE MECH IAW AMM 52-70-00. RE-INSTALLED DOOR. PRESSURIZED ACFT TO 5 PSI. NO DEFECT NOTED IAW AMM 21-30-00. ACFT OK FOR SERVICE.