As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN FWD ENTRY DOOR DID NOT SEAL PROPERLY UPON TAKEOFF+ DEPARTURE OVERHEAD LIGHT DID NOT ILLUMINATE. AIR RETURNED TO MDW NO; REMOVED AND REPLACED L1 DOOR GUIDE ARM IAW AMM 521121; REPLACED DOOR WARNING SWITCH S1147 IAW 527111 OPS CK GOOD