A MECH PULLED AND COLLARED THE WRONG TCASIi CIRCUIT BREAKER WHICH LED TO A RETURN TO LAND; WHEN THE FLC DISCOVERED THAT THEY WERE IN NON COMPLIANCE WITH THE ACFT'S MEL.

Narrative

THE EVENT BEING RPTED WAS AN AIR RETURN TO GSO; 10 MINS AFTER DEP. WE (THE CAPT AND I) BROUGHT THE ACFT INTO GSO FROM JAX. ON THE TRIP INBOUND WE NOTICED THE TCASII PORTION OF THE TCASII VSI UNIT WAS NOT FUNCTIONING PROPERLY. WE WROTE UP THE TCASII AND A MECH DEFERRED IT IN GSO. WE REVIEWED THE DEFERRAL AND VERIFIED THAT THE TCASII CIRCUIT BREAKER HAD BEEN PULLED AND TIE WRAPPED BY THE MECH AS PER THE MEL. WE DEPARTED GSO ON AN IFR FLT TO ORF. THE WX CONDITIONS WERE VFR AT GSO BUT WE EXPECTED TO ENTER INTO INST CONDITIONS ON THE DSCNT INTO ORF BECAUSE OF THE CURRENT AND FORECAST CONDITIONS AT THE ORF ARPT. AFTER DEP; WE NOTICED THE CAPT'S VSI AND TCASII UNIT WAS BLANK (INOP). AS DIRECTED BY THE CAPT; I LOOKED UP THE VSI IN OUR MEL. THE MEL SPECIFIED THAT 1 VSI MAY BE INOP FOR VFR FLTS ONLY. WE DISCUSSED THE MATTER AND DECIDED THAT THE TCASII MUST HAVE BEEN DEFERRED IMPROPERLY BY THE MECH AND SINCE WE WERE NOT IN IFR CONDITIONS BUT EXPECTED TO GO INTO IFR WX; WE NEEDED TO RETURN TO GSO AND HAVE THE VSI FIXED. AFTER LNDG IN GSO WE CONTACTED COMPANY OPS AND MAINT. A MECH IN GSO TOLD US THAT THERE WERE 2 CIRCUIT BREAKERS FOR THE TCASII AND THE WRONG ONE HAD BEEN PULLED. HE REMEDIED THE PROB. WE TESTED THE VSI AND FOUND ALL DEFERRALS IN ORDER AND FLEW THE TRIP TO ORF.