As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE, NR 1 PACK VALVE FAIL FOLLOWED SHORTLY BY NR 1 BLEED VALVE CLOSED FOLLOWED CHECKLIST AND AFTER RESET ONCE. FUMES APPEARED IN COCKPIT. RETURNED TO BOS NO OTHER ABNORMALITIES NOTED. NO FUMES IN CABIN. FUMES DISSIPATED AS SOON AS BLEED VALVE CLOSED. FOUND COUPLING BETWEEN DUAL TEMP CONTROL AND NR 1 ACM TUBE BLOWN REMOVED AND REPLACED COUPLING IAW EMB AMM 21-60-01. RUN PACK OPS CHECK GOOD IAW AMM 21-51-00. AIRCRAFT RETURNED TO SERVICE.