As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A STRONG SULPHUR BURNING SMELL WAS NOTICED IN THE CABIN AT FL 360 WHILE EN ROUTE TO IAH. THE RECIRCULATION FAN WAS SHUT OFF AND THE ODOR CEASED. WHEN THE FAN WAS TURNED ON DURING DESCENT THE ODOR RETURNED. THE FAN WAS SHUTDOWN AGAIN. THE AIRCRAFT LANDED WITHOUT FURTHER PROBLEM. TROUBLESHOOTING FOUND THE AVIONICS AIR COOLING FAN AT FAULT. THE FAN WAS REMOVED AND REPLACED IAW MM 21-58-12. LEAK AND OPERATIONAL CHECKS WERE GOOD.