What was found
FLT#288, LAX-BOS. {ETOPS) 'ENG 1 FIRE LOOP B FAULT ON CLIMB OUT AND BACK AGAIN IN CRUISE. ( ENGINE FIRE DETECTION SYSTEMS 2) LOOP B); ACCOMPLISHED TSMS 26-12-00-810-854 & 855. VENT LOOP B AND CORE AGB LOOP B RESISTANCES ARE W/IN LIMITS. VENT LOOP B: 3227 OHMS, CORE AGB LOOP B: 6840 OHMS, WITHIN LIMITS. BITE CHECK OF FDU PER 26-12-34, NO FAULTS. LAST 9 FLT LEGS, NO FAULTS. ENG 1 LOOP B IS OK FOR SERVICE. THIS CLEARS MDDR 485174. MX-4 UPDATED. MCC NOTIFIED. PLACARD REMOVED. (SUPPLEMENTAL INFORMATION ADDED TO DESCRIPTION)