SMOKE APPEARED IN AN ACR'S CABIN SHORTLY AFTER TKOF. THE FLT OPS MANUAL REQUIRED PROCS DIDN'T DISSIPATE THE SMOKE; SO THE FLC CHOSE TO RETURN LAND. A FLAP INDICATOR MALFUNCTIONED DURING DSCNT; AND REVERSE THRUST SELECTION WAS INOP AFTER LNDG. FAA MET THE ACFT.

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SHORTLY AFTER TKOF WE GOT A CALL FROM THE FLT ATTENDANTS THAT THERE WAS SMOKE IN THE CABIN AND ALL OF THE AFT LAVATORY SMOKE DETECTORS WERE GOING OFF. WE FOLLOWED PROCS IN OUR PLTS OPERATING MANUAL BUT THE SMOKE HAD NOT DISSIPATED. I WENT BACK TO DETERMINE TYPE OF SMOKE (FLT ATTENDANTS DID NOT KNOW WHAT ELECTRICAL SMOKE SMELLED LIKE) AND TO DETERMINE SEVERITY. IT WAS CONTINUING TO REMAIN IN THE MID TO AFT CABIN AREA AND HAD AN 'OILY' SMELL. WE DECIDED TO RETURN TO LAX TO HAVE ACFT CHKED OUT. DURING DSCNT THE SMOKE DID DISSIPATE. ADDITIONALLY; WHEN FLAPS WERE EXTENDED THE R SIDE FLAP INDICATOR TAPE STOPPED AT 10 DEGS BUT FLAPS DEPLOYED ON SCHEDULE WITH NO ADVERSE ROLL INPUTS. UPON LNDG AT LAX WE WERE UNABLE TO SELECT REVERSE THRUST. THIS DID NOT CAUSE A PROB DUE TO A LOW WT AND RWY LENGTH. AFTER SHUTDOWN WE SAW THAT ALL 3 CIRCUIT BREAKERS HAD POPPED ON THE THRUST REVERSERS. IT IS DIFFICULT TO SAY WHETHER THEY HAD POPPED AFTER PREFLT OR IF THEY HAD BEEN OUT BEFORE. MAINT FIXED ALL PROBS; RAN ALL ENGS; CYCLED REVERSE; AND FIXED FLAP INDICATOR. WE DEPARTED 1 1/2 HRS LATER AND COMPLETED FLT WITHOUT INCIDENT. I FEEL THE DECISION TO RETURN TO LAX WAS CORRECT. ALL APPLICABLE PROCS WERE FOLLOWED; AND PROB APPEARED TO STEM FROM THE #3 AIR-CONDITIONING PACK; BUT THIS COULD NOT BE CONFIRMED. THE THRUST REVERSER DID NOT HAVE ANY MALFUNCTIONS WHEN TESTED AND DID NOT REQUIRE MAINT. FAA REPRESENTATIVE HAD MET ACFT AT GATE AT LAX BUT DID NOT COMMENT OR HAVE MANY QUESTIONS FOR MYSELF. HE DID INSPECT THE LOGBOOK AND GO DOWN ONTO THE RAMP.