As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYSTEM: GEN PWR CONT CB POPPED AND APU SHUTDOWN AT GATE. FOUND GEN PWR CONT C/B INADVERTENTLY POPPED RESET C/B AND ACCOMPLISHED OPERATIONAL CHECK OF APU IAW B737-400 M/M 49-11-00 PG 501 OPS CHECK NORMAL NO DEFECTS NOTED AT THIS TIME.