As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, LEFT PACK LIGHT CAME ON WITH NO MASTER CAUTION. RAN CHECKLIST AND LIGHT STAYED ON. AFTER TESTING THE LIGHTS TEST LEFT PACK LIGHT WENT OUT. ADVISED MAINTENANCE, WAS ADVISED TO REPLACE THE LAMP. AFTER RELAMP OF LEFT PACK LIGHT, PACK LIGHT STAYED OUT. PUSHED THE MASTER CAUTION AND LEFT PACK LIGHT CAME ON BUT WENT OUT WHEN MASTER CAUTION PUSH TO RESET WAS PRESSED. ACFT GROUNDED. REMOVED AND REPLACED THE LT PACK TEMP CONTROL VALVE, LEAK AND OPS CHECK NORMAL IAW AMM 21-51-10. GROUND VERIFICATION CHECK GOOD.