As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE LOUD POP DOWN IN E&E COMPARTMENT FOLLOWED BY A DC STBY C/B POPPING AND LOSS OFF STBY POWER. RESET P6 PNL A2 C/B DC STBY INSPECTED E&E COMP FOR ABNORMALITIES CHECKS OK. STBY POWER TRANSFER OPS NORMAL. PERFORMED SHORT TEST PER M/M - NTF.