What was found
SHORTLY AFTER STARTING THE DESCENT NOTICED LEFT NR 1 PACK LIGHT ILLUMINATED, MASTER CAUTION DID NOT ILLUMINATE. DID NOT LOOK AT THE PACK TEMP GAUGE. ACCOMPLISHED QRH PROCEDURE, NR 1 PACK LIGHT DID NOT EXTINGUISH PUSHING THE TRIP RESET BUTTON NOR DID IT EXTINGUISH WITH MASTER CAUTION RESET. THE NR 1 PACK LIGHT DID EXTINGUISH WITH A SECOND ATTEMPT WITH MASTER CAUTION RESET. ACFT GROUNDED. PERFORMED PACK TEMPERATURE CONTROL BITE PROCEDURE IAW FIM 21-62 TASK 801. NO FAULTS. PERFORMED TROUBLESHOOTING IAW FIM 21-53 TASK 815. PACK OPERATED ON GROUND, NO PACK LIGHT EVER ILLUMINATED, PACK OPERATING TEMP NORMAL. NO PREVIOUS HISTORY LAST 30 DAYS. CHECKED GOOD FOR SERVICE.