As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
During Flight # 2807, Cargo Door Warning light coming on after Takeoff. Air return to MSP. Maintenance found switch 7DD stuck at close position due to wrong adjustment re-adjusted switch 7DD and 19DD IAW SF340 MM Chap 52-70-15-4. All checks good.