As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GNDED. FUMES IN MID TO AFT CABIN WITH A/C PACKS ON WITH APU. WHITE HAZE ASSOCIATED WITH FUMES. SMELLED LIKE BURNING PLASTIC. REPLACED APU IAW 26L31049003 & ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK. UPDATED SECTION 3 & 4 INFORMATION.