A B737-300 HOLDING AT 12000 FT DECLARED AN EMER AND DIVERTED DUE TO CABIN ATTENDANT RPT OF ELECTRICAL BURNING ODOR. CAUSED BY FAILED COOLING FAN.

Narrative

IN HOLDING AT ZZZ; CAPT AND FO BOTH SMELLED FAINT BUT OBVIOUS ODOR OF SMOKE. SHORTLY THEREAFTER; WE HEARD FLT ATTENDANT CALL BUTTONS GOING OFF IN CABIN AND SHORTLY AFTER THAT THE 'A' FLT ATTENDANT RPTED VIA INTERPHONE THAT PAX SMELLED SMOKE AND SO DID SHE. THERE WAS NO VISIBLE SMOKE. FLT ATTENDANTS INSPECTED CABIN INCLUDING LAVATORIES THOROUGHLY FINDING NO EVIDENCE OF FIRE OR VISIBLE SMOKE. THE CAPT INFORMED CTR THAT WE SMELLED SMOKE IN THE CABIN AND QUERIED IF WE WOULD BE ABLE TO GET INTO ZZZ SINCE THE REASON FOR THE HOLD WAS NOT KNOWN BY CREW. CTR IMMEDIATELY CLRED US DIRECT TO ZZZ AND WE SET UP FOR ILS TO RWY 26R; DECLARING AN EMER. IN THE PROCESS OF SETTING UP; THE FLT ATTENDANT RPTED THAT THE SMELL HAD SUBSIDED. APCH SWITCHED RWY TO RWY 26L. ALTHOUGH BUSY; IT WAS AN EXPEDITIOUS APCH WITH ATC PRIORITY AND AN UNEVENTFUL LNDG. WE EXITED RWY; STOPPED; AND HAD A VISUAL INSPECTION FROM ARPT FIRE EQUIP -- NO PROBS SEEN. WE TAXIED TO GATE AND DEPLANED. FIRE AND MAINT INSPECTED THE ACFT AND FOUND NOTHING IN THE CABIN. FO HEARD LOUD NOISE FROM FORWARD CARGO BAY ON OUTSIDE INSPECTION; SUBSEQUENTLY FOUND BY MAINT TO BE A FAULTY EQUIP COOLING FAN. IT WAS INOP'ED; AND DEFERRED. WE FLEW THE ACFT NEXT LEG TO ORD WITHOUT INCIDENT. FLT ATTENDANTS DID EXCELLENT JOB OF CTLING A SOMEWHAT PANICKY PAX DURING THE EVENT; AS WELL AS COMMUNICATING WITH THE COCKPIT AND PREPARING FOR THE QUICK LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CAPT STATED THERE REALLY WAS NO SMOKE VISIBLE BUT MAINLY A BURNING ELECTRICAL ODOR. THE E&E COMPARTMENT COOLING FAN HAD FAILED AND NO CIRCUIT BREAKERS WERE FOUND TRIPPED. FAN WAS FOUND AT THE DIVERSION STATION BY THE FO ON THE WALKAROUND CHK AND INSPECTED BY MAINT AND THEN DEFERRED PER THE MEL.