As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TEN MINUTES INTO FLIGHT, PILOT NOTICED THAT THE AIR CONDITIONER STOPPED WORKING AND SHORTLY NOTICED SMOKE IN COCKPIT. TURNED OFF THE A/C AND THE SMOKE WENT AWAY. RETURNED TO BASE. ON EXAMINATION BY THE MX, IT WAS DETERMINED THE AC COMPRESSOR HAD FAILED INTERNALLY. AFTER REPLACING THE COMPRESSOR, THE AC OPERATED NORMALLY AND NO SMOKE WAS OBSERVED IN THE COCKPIT.