What was found
STARTED APU ON GROUND AFTER LANDING, WITH BLUE APU GEN OFF LIGHT ON. ATTEMPTED TO CONNECT APU GEN. ENGINE GENERATORS DISCONNECTED APU DID CONNECT FOR A MINUTE THEN WE LOST AC POWER. APU GEN OFF LIGHT REMAINED ON BUT HAD NO INDICATION OF VOLTS OR FREQUENCY. SHUT DOWN APU. PER MOC REQUEST INSPECTED APU FIRE CONTROL PANEL IAW AMM 26-22-03 AND RESEATED SHUTTOFF HANDEL. APU GEN APPLIED NORMALLY IAW AMM 24-22-00. OPS CHECK GOOD.