As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED TO PLATFORM, APU OUT OF SERVICE AND ENGINE GENERATORS WITHOUT INDICATION OF VOLTAGE AND FREQUENCY. CIRCUIT BREAKERS B1-204, B1-205 AND B1-206 WERE CHECKED AND SWITCH SELECTOR S1-99 WAS REPLACED IAW MM 24-21-01, TEST CORRECT.