What was found
AFTER APU START UP AND THE SELECTION OF THE BLEED AIR TO "ON", THE F/A'S REPORTED SMOKE IN THE CABIN. C/W AIR CONTAMINATION CHECKLIST. CREW REPORTED SMOKE DISAPATED AFTER SEVERSL MINUTES. APU BLEED AIR WAS NEVER SELECTED OFF. INSPECTED APU COMPARTMENT, AND TAIL OF ACFT. NO LEAKS OR DAMAGE NOTED TO APU. NOTICED DEICE FLUID RESIDUE INSIDE APU COMPARTMENT AND ON OUTSIDE THE TAIL OF ACFT. CLEANED DEICE FLUID RESIDUE INSIDE APU COMPARTMENT AND AROUND TAIL OF ACFT. GROUND RAN NR 1 AND NR 2 ENGINES WITH BLEED AIR SELECTED ON, NO SMOKE OR SMELLS NOTED. SUSPECT RESIDUAL SMELL IN CABIN FROM INITAL APU BLEED AIR START UP. APU BLEED AIR MEL AS A PRECAUTIONARY MEASURE. MEL CLEARED BY RAN APU WITH BLEEDS ON FOR ONE HR IAW AMM 49-00-00-710-801, NO SMOKE OR ODORS IN CABIN CLEARED MEL ACFT OK FOR CONTINUED SERVICE.