Narrative:

Flight attendants reported smoke from a video monitor in the aft section of the aircraft. The captain coordinated with the flight attendants and off duty mechanic to isolate the problem as I began a descent and diversion to ZZZ. They quickly isolated the problem by turning off the master switch to the video system. Smoke stopped very soon after the report. Descent and approach to ZZZ were uneventful. An emergency was declared. An on duty mechanic in ZZZ verified the video system was properly secured with circuit breakers pulled and system master switch off. Also verified no fire or smoke hazard continued to exist.

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Original NASA ASRS Text

Title: MD90 DEVELOPED SMOKE IN CABIN. FLT CREW DECLARED AN EMER AND FLT DIVERTED WHILE SOURCE WAS IDENTIFIED.

Narrative: FLT ATTENDANTS RPTED SMOKE FROM A VIDEO MONITOR IN THE AFT SECTION OF THE ACFT. THE CAPT COORDINATED WITH THE FLT ATTENDANTS AND OFF DUTY MECH TO ISOLATE THE PROB AS I BEGAN A DSCNT AND DIVERSION TO ZZZ. THEY QUICKLY ISOLATED THE PROB BY TURNING OFF THE MASTER SWITCH TO THE VIDEO SYS. SMOKE STOPPED VERY SOON AFTER THE RPT. DSCNT AND APCH TO ZZZ WERE UNEVENTFUL. AN EMER WAS DECLARED. AN ON DUTY MECH IN ZZZ VERIFIED THE VIDEO SYS WAS PROPERLY SECURED WITH CIRCUIT BREAKERS PULLED AND SYS MASTER SWITCH OFF. ALSO VERIFIED NO FIRE OR SMOKE HAZARD CONTINUED TO EXIST.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.