As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT CHECK FIRE DETECT WARNING AND MASTER WARNING LIGHTS ILLUMINATED ALONG WITH NR 2 FAULT B ON FIRE PROTECTION PANEL. ALL ENGINE PARAMETERS WERE NORMAL. CIRCUIT BREAKER K8 ON LEFT ESSENTIAL BUSS FOUND POPPED. RESET CIRCUIT BREAKER AND FOUND, WHEN NR 2 SELECTED TO LOOP B ONLY LOOP TEST INTERMITTENTLY. REMOVED AND REPLACED FIRE DETECTION UNIT AND REPAIRED CHAFED WIRES AT C/P'S 26113P3 AND P5. OPS CHECK GOOD IAW 26-11-00.