As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CARGO DOOR OPEN INDICATION ON EICAS DURING CLIMB, NO PRESSURIZATION FAULTS. FLIGHT CREW ELECTED TO TURN BACK. FOUND TO BE THE DOOR LATCH MECHANISM AT FAULT. REPLACED ON SPRING SPACER AND PIN AFFECTED. SPRING MPN 601-35082-1SPACER P/N NAS43DD4-18PIN P/N MS 16562-38