As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FLIGHT LEVEL 250, LEFT PACK COOLING DOOR WAS CLOSED AND PACK TEMPERATURE REACHED 150 CELSIUS ACCOMPLANIED BY ACRID SMELL AND SMOKE IN COCKPIT. REMOVED AND REPLACED 35 DEGREE CONTROL VALVE LEFT SIDE. CHECKED LEFT COOLING AND EXHAUST DOORS. ALL CHECK NORMAL. RAN APU LEFT PACK ON, NO SMELL OR SMOKE NOTED.