What was found
FLT 920 - PHX-PDX - EE - CARGO SMOKE DETECTOR FAULT. MAINTENANCE REMOVED AND REPLACED THE SMOKE DETECTOR CONTROL UNIT AND CARGO SMOKE DETECTOR. OPERATIONAL CHECK WAS GOOD. CARGO SMOKE DETECTOR, MFR SIEMENS, MPN PPA1102-00, MSN 2199, TOTAL TIME 21393, TOTAL CYCLES 8207, TIME SINCE REPAIR 406.