What was found
DIVERSION FOR ELECTRICAL PWR LOSS, REF LP 7583866, APPROX 1.4 HRS INTO FLIGHT NR 1 EFIS SCREENS WENT BLANK, STBY PWR AC BUS WENT TO ZERO VOLTS, ZERO FREQS, PRESSURIZATION FAILED; AFTER 5 SECS IT ALL CAME BACK, NR 1 BUS ALSO FLICKERED OFF. REPLACED TRANSFER RELAY R3, GENERATOR DRIVE, AND STBY PWR PANEL. AC POWER CHECK GOOD.