What was found
CAPT VSI INOP ON TAXI-OUT APPROX 20 MIN INTO TAXI. REPLACED CAPTS VSI PER AMM. OPS CHK NML. PART ROBBED FROM A/C 173. MPN 066-50001-1001 S/N 10139 CAPT POS. AC RTB TWICE FOR SAME PROBLEM. FIRST IND REMOVED AND REPLACED WITH PREV SHOPHIST. 2ND IND SAME THING BUT DIFFERENT SHOP HIST. C/B WAS ALSO REMOVED AND REPLACED ON 1ST RTB DUE TO ELEC FUME REPORTED. CONNECTOR AND WIRING WERE CHECKED PRIOR TO 3RD IND. REPLACED C/B C586 AND REPLACED CAPT IVSI PER AMM. OPS CHK NML, NO FUMES PRESENT.