As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING AND CLEARING RUNWAY, TRANSFERED BLEEDS TO APU OPEN AND COCKPIT FILLED WITH SMOKE AND A STRONG BURNING ODOR. RAN ENGINES EXCESSIVELY WITH BOTH PACKS ON. NO SMOKE OR BURNING ODOR. TRANSFERRED BLEEDS OVER TO APU. RAN FOR 1/2 HR, NO SMOKE OR BURNING ODOR. OPS CHECK GOOD. UNABLE TO DUPLICATE.