What was found
AT FL340, LT ENGINE N1 DROP DOWN TO IDLE, NO INDICATION OF OTHER ABNORMAL. CREW DECLARED AN EMERGENCY AND DIVERTED BACK TO CVG. AFTER TROUBLESHOOTING MTX FOUND L ENGINE PUSH-PULL CABLE CONTROL BOX DISLODGED FROM MEC AT THE HOUSING BODY. GAINED ACCESS TO, THEN SECURED HOUSING BODY BOLTS, THEN REINSTALLED SAME CONTROL BOX PER AMM 76-11-02. POST-WINDMILL INSPECTION C/W AMM 72-00-00/601. NO FINDINGS. SEE L/P 39512-02/1. A/C VERIFIED NO ETOPS.AND RETURNED A/C TO SERVICE