As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O ENG EICAS MSG LT ENG OVHT LP1/LP2 FIRE OVHT SYS FAIL LIGHT ON. REPLACED M687 AND M688 LEFT OVHT LOOP 1 AND 2 CARDS, INSPECTED LEFT ENG PNEU DUCTS AND CLAMPS. RETORQUED CLAMPS. RAN ENGINES TO T/O POWER FOR SEVERAL MIN, NO OVHT MSG OR CAUTION. INSPECTED OVHT LOOPS 1 AND 2 LEFT ENG AND WIRING, NO TROUBLE FOUND.