What was found
NR 1 ENGINE FIRE LOOP B FAULT ILLUMINATED. ACFT GROUNDED. VERIFIED THE NR 1 ENGINE FIRE LOOP B FAULT. FIRE LOOP A TESTED NORMAL. NR 1 ENGINE OVERHEAT DETECTION SET TO A. ACCOMPLISHED FIM 26-10 TASK 801. NR 1 ENGINE LOOP B FAULT REMAINS. VERIFIED THE NR 1 ENGINE LOOP SWITCH IN NORMAL. OPS TESTED GOOD IAW AMM 26-10-00. NO FAULTS ON APU AND ENGINE FIRE DETECTION LRU IAW FIM 26-10 TASK 801. OPENED AND INSPECTED AND SHOOK DOWN WIRING ON THE NR 1 ENGINE AT ALL LOOP CONNECTIONS AND DISCONNECTS. NO FAULTS FOUND. ALL TESTS STILL PASS. NO HISTORY LAST 30 DAYS. GROUND VERIFICATION GOOD.