What was found
*****ODI EVENT******D: WE WERE WAITING ON THE RAMP WITH ONLY OUR APU UP (AS WE HAD A FLOW TIME FOR ABOUT AN HOUR AWAY) WHEN WHITE SMOKE CAME RUSHING INTO THE COCKPIT. FAS REPORTED HAZE ON THEIR END IN THE BACK OF THE CABIN. UPON TROUBLESHOOTING FOUND LH PACK TO BE CAUSING THE SMOKE. VERIFIED RH PACK OPERATING NORMALLY. RECEIVED LH PACK AUTOFAIL MESSAGE AND NOTICED THE LH PACK OVER-TEMPING. FOUND B1 CODE # 211941.C: MEL 21-51-1GCAT: C DUE DATE: 24 JUN 2023WE WERE WAITING ON THE RAMP WITH ONLY OUR APU UP (AS WE HAD A FLOW TIME FOR ABOUT AN HOUR AWAY) WHEN WHITE SMOKE CAME RUSHING INTO THE COCKPIT. FAS REPORTED HAZE ON THEIR END IN THE BACK OF THE CABIN. (FLT 3801 FILED OPEN)JUN 15, 2023 STATION: AGS--UPON TROUBLESHOOTING FOUND LH PACK TO BE CAUSING THE SMOKE. VERIFIED RH PACK OPERATING NORMALLY. RECEIVED LH PACK AUTOFAIL MESSAGE AND NOTICED THE LH PACK OVER-TEMPING. FOUND B1 CODE # 211941. DEFERRED LH PACK PER MEL 21-51-1G.