What was found
ON CLIMBOUT, FIRE/OVERHEAT NR 1 EICAS MESSAGE DISPLAYED WITH STATSS MESSAGE NR 1 FIRE LOOP A, DISPLAYED. PERFORMED PNEUMATIC DUCT LEAK IAW MM 36-11-00, NO LEAKS FOUND. PERFORMED TROUBLESHOOTING ON NR1 ENGINE FIRE DETECTION, INSPECTED UPPER AFT, LOWER AFT, LOWER FWD FIRE DETECTOR LOOPS, NO TROUBLE FOUND. MEASURED RESISTANCE OF THE DETECTOR ELEMENTS AND OK. CHECKED WIRING AND OK; AS PRECAUTION; UPPER AFT LOOP REPLACED IAW MM 26-11-02 AND ALL TESTED NORMAL.