As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTS ENG 1 AND ENG 2 FIREX BOTTLE B FAIL ON EICAS. REMOVED FROM SERVICE. C/W FIM TASK 26-21-00-810-810-A00. ENG 1 & ENG 2 FIREX BTL B FAIL MESSAGE EXTINGUISHED. PERFORMED ENGINE FIRE DETECTION LOOP OPERATIONAL CHECK IAW AMM TASK #26-11-00-710-802-A OPERATIONAL TESTED GOOD. MESSAGES REMAINED EXTINGUISHED. NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE. NO PARTS REPLACED.