As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE IN CABIN DURING CRUISE AT FL250. INSPECTED PACK SYSTEM, FOUND #200 ACM SIEZED W/ MELTED DUCTS ON #200 DUAL TEMP CONTROL VALVE. R/R'D DUCTS ON #200 DUAL TEMP CONTROL VALVE IRW AMM 21-60-01. R/R'D #200 ACM IRT AMM 21-61-03. OPS AND LEAK CHECK GOOD WITH NO VISIBLE SMOKE IN CABIN.