As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 CSD HIGH OIL TEMP LIGHT ILLUM CLIMBING THRU 15000 FT. DISCONNECTED CSD PER POM. STARTED APU AT 19000 FT THEN AT FL250 THE APU GEN DROPPED OFF LINE. DIVERTED TO MCO. FOUND CSD OVERSERVICED. SERVICED TO CORRECT LEVEL. CHECKS NORMAL ON ENGINE RUN. FWD TO MCO AND PLACARD DUE TO HISTORY. REPLACED APU GCU. APU GENERATOR OPN NORMAL.