As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#8390, ORD-BOS. ODOR EVENT AFT GALLEY @ ROW 26-29 APU WAS OFF SMELL FOR ABOUT 3 HOURS STRAIGHT DESCRIBE AS ROTTEN EGG TRY TO TROUBLE SHOOT BY S/O PACK 2 SMELL CONTINUE; COMPLIED WITH INFO NOTICE 2017-T015 STEP 1 ISOLATED FAULT TO TYPE 10 PERFORMED LEVEL B ECS DECONTAMINATION REF AMM 21-00-00 AND R/R BOTH CABIN RECIRCULATION FILTERS REF AMM 21-21-41 NO FURTHER ODOR NOTED A/C OK TO RETURN TO SVC.