As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO PWR GROUND SERVICE BUSS CABIN LIGHTS OUT/GALLEY PWROUT/ENT SYSTEM OUT. NO LAND 3 IN FDE WAS ABLE TO RESTORE USING APU PWR HOWEVER COULD RESTORE BACK TO FLT CONFIG DUE TO GROUND SERVICE BUS NECESSARY FOR FLT CREW ELECTED TO RTN ATL. REPLACED GSSR.