As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU ELECTRICAL POWER WILL NOT CONNECT (EITHER SIDE). AC VOLTS ZERO, FREQUENCY ZERO. ACFT GROUNDED. STARTED APU, VOLTS & FREQUENCIES SHOWED ZERO BUT ONCE PLACED ONLINE, VOLT & FREQUENCIES SHOWED NORMAL OUTPUT AND HOLDS THE BUSS. CYCLED POWER MULTIPLE TIMES. OPS CHECKED NORMAL.