As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW DECLARED AN EMERGENCY AND DIVERTED. DURING CRUISE AT FL 340 NOTICED A STRONG BURNING ELECTRIC ODOR. ODOR DISSIPATED DURING DESCENT. NOTICED CB X18 RECIRCULATING FAN SUPPLY CIRCUIT BREAKER WAS TRIPPED. ACCOMPLISHED TSM 24-00-00-810-823A AND TSM 05-50-00-810-831A AND FOUND LT RECIRCULATING FAN TO BE THE SOURCE OF THE EVENT. REPLACED RECIRCULATION FAN & CHECK VALVE IAW 21-21-51-400-001-A. OPS CHECKED OK.