What was found
AT ABOUT 300FT AGL AFTER TAKEOFF, F/O`S CADC FAILED WITH FLAGS IN AIRSPEED AND ALTIMETER AND BOTH FLIGHT DIRECTORS FAILED. FOUND C/B F12 POPPED. PLACED BOTH CADCS ON NR 1 AND F/O`S INSTRUMENTS BEGAN TO INDICATE NORMAL. ALTITUDE SELECT WINDOW FLIGHT GUIDANCE PANEL WAS BLANK, AUTOTHROTTLES WOULD NOT TURN ON. SWITCHING FROM AP1 AND AP2 DID NOT HELP. ON FINAL APPROACH 5 MINS LATER FLIGHT DIRECTOR BEGAN TO WORK BUT AUTOTHROTTLES WOULD NOT ENGAGE. BOTH FMAS WENT BLANK AND AFTER 2 MINUTES SELECT WINDOW BEGAN TO WORK. ON FINAL ALL FMA WINDOWS WORKED. FOUND NR 2 CADC BAD. REPLACED NR 2 CADC AND CHANGED CIRCUIT BREAKER FOR NR 2 CADC. ALL TEST CHECKED OK.