As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 3297 AT 18,000 FT, SMOKE INFLIGHT DECK AND CABIN. CREW HAD SMOKE GOGGLE ON, SUPPLEMENTAL A/C WAS TURNED OFF AND CONDITIONS IMPROVED. AIR RETURN TO MEM. MAINTENANCE INVESTIGATED AND FOUND SUPPLEMENTAL A/C COMPRESSOR MOTOR AT FAULT. EXCESSIVELY ARCING. MAINTENANCE REMOVED AND REPLACED SUPPLEMENTAL A/C COMPRESSOR MOTOR IAW ARR 8/8/2.