As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THERE IS A STRONG ODOR OF BURNING RUBBER WITH A SLIGHT HAZE IN THE CABIN. PERFORMED TROUBLESHOOTING PER MM. 21-52-00 AND FOUND ODOR TO BE COMING FROM COCKPIT ACM. REMOVED AND REPLACED THE AFT ACM. OPS TESTED WITH NO FURTHER DEFECTS FOUND IAW AMM 21-00-00 AND COMPLIED WITH SERVICE LETTER SL750-21-02R4.