As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE AFT BLOWER CHECK C, -AFT DET FAN- MESSAGE DOES NOT SHOW ON EICAS. NR 2 FAN DOES NOT START UP AND -CARGO DET AIR- MESSAGE STAYS. FOUND BAD RELAY K334 AFT CARGO SMOKE DET BLOWER TDC RELAY. REPLACED PER B767 WDM 26-16-21. OPS CHECKS NORMAL. SUSPECT RELAY DAMAGED BY REPEATED CYCLING.