What was found
FLT 195, JFK-LAS, AT 34,000 AFT AVIONICS COMPARTMENT FIRE INDICATION SOUNDED, QRH WAS PERFORMED AND FLIGHT ATTENDANTS REPORTED NO INDICATION OF SMOKE/FUME/FIRE. DIVERTED TO DAY. PERFORMED AFT AVIONIC RACK/LTV SYS INSPECTION AS PER AMM 23-39-00. NO DISCREPANCIES NOTED. AFT AVIONICS FIRE FALSE INDICATION, FOUND COOLING FAN SEIZED. REMOVED AND REPLACED RACK COOLING FAN, OPS NORMAL PER 23-39-00.