As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: A REPEAT WRITE UP THE FLIGHT ATTENDANTS REPORTED ROTTEN EGG SMELL IN AFT GALLEY. ACCOMPLISHED WORK CARD 09L00021001. FOUND CLOGGED DRAIN VALVE. CLEAN GRAY WATER SYSTEM DRAIN. PER AMM 38-31-00. OPS CHECKED GOOD, NO MORE ODOR.