As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THE FWD GALLEY CHILLER PRODUCING A HIGH PITCH NOISE. UPON TURNING CHILLER OFF, FLIGHT ATTENDANT REPORTS A BURNING ODOR. FLIGHT RETURNED TO THE GATE. MX TROUBLESHOT CABIN AIR QUALITY IAW JOB CARD 26L00021001 ALONG WITH CABIN ODOR REPORT. FOUND FWD GALLEY CHILLER TO BE CAUSE. R & R FWD GALLEY CHILLER IAW AMM 25-34-51.