As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS MSG "ENG 1 AND 2 FIREXBTL A FAIL" INTERMITANTLY DURING CLIMB, EXTINGUISHED AFTER LEVEL OFF AND DIDNT COME BACK ON. C/A-PERFORMED FIM TASK 26-21-00-810-809A. FOUND TO BE A TRANSITORY CONDITION OF THE GENERIC I/O MODULE 3. OK FOR SERVICE.