As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEN#1 LOW OIL PRESS ILLUMINATED, LOW OIL ALSO ON VOLTIMETER. GEN WAS DISCONNECTED. APU DID NOT START AFTER 3 ATTEMPTS. CORRECTIVE ACTION: WAS REPLACED THE FILTER ELEMENT OF THE LUVE ALL FILTER FOR THE GENERATOR DRIVE OIL COOLER. WAS REPLACED IGNITION UNIT AND PERFORMED APU OPERATION TEST