As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE SWITCH ILLUMINATED INTERMITTENTLY FOR SEVERAL HOURS. A FEW TIMES FIRE APU WARNING EICAS MESSAGE ALSO DISPLAYED FOR A SPLIT SECOND. ALSO, CAN HEAR APU FIRE SWITCH DISCONNECTING.(<P>REMOVED AND REPLACED AFOLTS CARD A22 PER AMM 26-10-01/401. INSPECTED FIRE CONTROL MODULE WIRE BUNDLES, NO CHAFFING NOTED. ALL ELECTRICAL CONNECTORS SECURE. INSPECTED FIRE LOOPS IN APU COMPARTMENT, NO DEFECTS NOTED. </P>)