As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK/IAD - FLT 6473 - DURING CRUISE AT 1414 HOURS ON 4-5-98, MADE AN UNSCHEUDLED LANDING AND AN EMERGENCY DESCENT DUE TO SMOKE IN CABIN. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED EVAPORATOR BLOWER MOTOR AND RESISTOR INSIDE CAPACITOR MODULE. OPS CHECK OK. AIRCRAFT WAS RELEASED AND RETURNED TO SERVICE. REF: OPERATOR CONTROL NR 98ZZZX1744. (X)