What was found
FLT 1992, TPA-BOS. FL 330 VENT EXTRACT FAULT LOUD BUZZ FOLLOWED BY SLIGHT ELECTRICAL BURNING SMELL AVIONICS VENT EXTR CIRCUIT BREAKER POPPED (EXTRACT FAN - NO AVNCS SYS FAULT ECAM CAUTION); R & R EXTRACT FAN IAW AMM 21-26-51. OPS CHECK GOOD. MX4 UPDATED, PLACARD REMOVED, MDDR CLEARED.