As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HEAVY MUSTY DIRTY SOCK SMELL COMING FROM AIR VENTS-INSPECTED APU COM/AREA FOUND HEAVY APPLICAION OF DE-ICE FLUID APU AIR INTAKE. RAN NR 1 & NR 2 ENGS WITH PACKS FOR 10 MIN. USING XTERNAL AIR START NO DIRTY SOCKS OR ADVERSE SMELL. AIR QUALITY NORMAL. MX IAW 71-00-00 XFERED APU TO DMI(SEE BELOW)