What was found
SMOKE IN CABIN - WHILE TAXIING TO RUNWAY, SEAT ROW 11 RT VIDEO SCREEN DID NOT COME DOWN AND WAS FOLLOWED BY SMOKE IN THE CABIN, AIRCRAFT RETURNED TO GATE. ISSUED MEL 25-22-03, COND. 2 (VIDEO SAFETY DEMO SYSTEM INOP). WHEN AIRCRAFT RETURNED TO PHX ON 10/11/2003 MAINTENANCE REMOVED AND REPLACED THE VIDEO MONITORING AND TAPING UNIT IAW AMM 23-36-22, AND 23-36-44, OPERATIONAL CHECK WAS GOOD. PART NAME; TAPING UNIT, MFG; SONY TRANS; P/N; 700-1545-001, S/N; 2513, TT; 33331, TC; 13707