As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED BURNING SMELL IN THE COCKPIT DURING APPROACH INTO PHL, DECLARED EMERGENCY AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT PER EMB AMM AND FOUND THE PACK NR 1 ACM WAS AT FAULT. MAINTENANCE PLACED THE NR 1 PACK ON MEL 21-51-00-1. THE A/C WAS THEN RETURNED TO SERVICE. MAINTENANCE REMOVED AND REPLACED ACM NR 1 TO CLOSE MEL 21-51-00-1.