As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE FL370 GOT CABIN SMOKE ALERT, CAME ON THEN WENT OUT THEN CAME BACK ON. FOLLOWED RED TABS AND DIVERTED TO PDX. TEST OF SMOKE DETECTOR PER MM26-14-01-5. MSC FAULTED ITSELF ON LEG 10, 20, & 30. INSPECTED SMOKE DETECTORS & WIRING & CEILING AREA FROM SMOKE CURTAIN TO AFT PRESSURE BULKHEAD. INSPECTED HF COUPLERS FOR DAMAGE. ALL CHECKS NORMAL. R&R MSC PER M-M 31-42-01-4. OPS CHECK NORMAL.