As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ON FINAL APPROACH CREW OBSERVED ELECTRICAL BURNING SMELL FOLLOWED BY PACK MODEL & STBY COOLING MSG ON AIR SCHEMATIC PACK ACM L STATUS MSG POST FLIGHT. ACCOMPLISHED SOF CARD 78L00021001. FOUND L/H ACM FROZEN. REF MIC4494149 MAINTENANCE REPLACED AIR CYCLE MACHINE REF. DMC-B787-A-21-52-02-01A-720A-A.