As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ATTENDANT REPORTS A LOUD SQUEAL SOUND COMING FROM ROW 8 WE WERE AT 36000 FEET, CABIN ALT 7600 FT & CABIN PRESSURE AT 7.7 STEADY NO FLUCTUATIONS. SLIGHT BURNING SMELL THROUGHOUT CABIN WHEN RUNNING PACK NR 2. ALSO HAS A DIFFERENT SOUND WHEN SPOOL DOWN. R & R RT AIR CYCLE MACHINE IAW AMM 21-51--03. GND OPERATIONS CHECKED 30 MIN NO BURNING SMELL NOTED. OPERATIONS CHECKED GOOD.