As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CARGO FIRE LIGHT FAILED TO ILLUMINATE DURING ENGINE APU CARGO FIRE OVERHEAT TEST. EICAS MESSAGE (AFT CARGO FIRE) WAS NOT DISPLAYED. AFT CARGO ARM SWITCH DOES NOT ILLUMINATE DURING FIRE TEST OR MASTER TEST. REPLACED RECEPTACLE. OPS CHECKED GOOD.