As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CARGO DOOR LIGHT ON FLIGHT ENGINEERS PANEL ILLUMINATED DURING FLIGHT. ALSO OBSERVED DOOR WARNING LIGHT AND NR 4 HOOK UNLOCK LIGHT ON, ON CARGO DOOR OPERATING PANEL ILLUMINATED. PERFORMED APPROPIATE CHECKLIST. AIR TURNBACK TO (YIP). FOUND LOOSE BRACKET FOR HOLDING HOOK LATCH SWITCH. SECURED AND ADJUSTED SWITCH IAW AERONAUTICAL ENGINEERS INC 727 M/M, OPS CHECK GOOD.