As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU GENERATOR POWER INOP INTERMITTENTLY. BITE TEST BPCU SHOW "REPLACE APU GCU" MSG. REPLACED APU GCU UNIT, NO HELP. NEED TO REPLACE AUXILARY POWER BREAKER C905 IN P34 PANEL. REPLACED AUX POWER BREAKER C905 PER MM. ACP GROUND TEST AND OPS CHECKS GOOD.